American children whose genetic roots strongly reach back to Africa are less sensitive to insulin-a factor important in the development of type 2 diabetes-than those whose ancestors hailed heavily from Europe, according to study results released today. Rather than relying on broad categories of race, such as black or white, researchers in diabetes and obesity from the Keck School of Medicine of USC and the University of Alabama at Birmingham analyzed a group of children for 20 key genetic markers found far more often in those of African descent than those of European descent. They found that the more African-origin markers in children’s genetic makeup, the less their bodies responded to insulin-and the more insulin in their blood.
A new non-invasive therapy for liver cancer patients who cannot be helped by surgery or organ transplantation is being evaluated by researchers at the Indiana University School of Medicine. The Phase I clinical trial at the IU Cancer Center uses extracranial stereotactic radioablation (SRA) as a potential new treatment for hepatocelluar carcinoma, a cancer that originates in the liver, or for liver metastasis from other sites.
Sometimes finding out what doesn?t matter in science is just as important as finding what does. That?s the case for a study that looked at the function of the viral protein, MTase1. Researchers found that the rate of virus replication in tissue culture was not affected when MTase1 was removed. The finding is important as researchers look for what proteins are essential and how they function in cells, potentially providing answers to everything from insect control to the control of human diseases such as smallpox.
Researchers have discovered how to transfer the optical properties of silicon crystal sensors to plastic, an achievement that could lead to the development of flexible, implantable devices capable of monitoring the delivery of drugs within the body, the strains on a weak joint or even the healing of a suture. The discovery is detailed in the March 28 issue of Science by a team that pioneered the development of a number of novel optical sensors from silicon wafers, the raw starting material for computer chips.
A better understanding of the new “smelling” capabilities of human sperm cells may lead to advances in contraception and fertility treatments. A new study identifies a novel odorant receptor on human sperm and shows how activating this receptor causes the sperm to make a beeline for a target. In a study appearing in the 28 March issue of the journal, Science, German and U.S. researchers report that the binding of certain compounds to the new odorant receptor (hOR17-4) found on the surface of sperm cells, triggers a series of physiological events that may result in the directed movement of human sperm. In this chemosensory response, the sperm cells travel toward elevated concentrations of a sperm-attracting substance called “bourgeonal.”
Researchers have completed sequencing the genome of Bacteroides thetaiotaomicron, one of the most prevalent bacteria that live in the human intestine. “Now that the draft sequence of the human genome is complete, it’s critical that we study the environmental forces that regulate our gene expression,” says principal investigator Jeffrey I. Gordon. “Humans enjoy mutually beneficial relationships with billions of bacteria that live in our gut. Discovering how these microbes manipulate our biology to benefit themselves and us should provide new insights about the foundations of our health and new therapeutic strategies for preventing or treating various diseases.”
Patchy woods–common in cities and suburbia, and even in rural areas–may have more Lyme disease-carrying ticks, which could increase risk of the disease in these forest remnants, scientists have found. While forest fragments generally have fewer species than continuous habitat does, some species actually fare better in small patches, according to biologist Felicia Keesing of Bard College in Annandale, NY, and her colleagues. Lyme disease incidence is rising in the United States, and is in fact far more common than West Nile fever and other insect-borne diseases. Forest fragmentation could explain the increase.
Using a laser beam scalpel so fine it could inscribe words on the surface of a fly egg, researchers have snipped their way to a new understanding of a key process in a fruit fly’s embryonic development. The process, called dorsal closure, is the complex mechanism by which the embryonic skin of the fruit fly Drosophila knits itself together to protect its innards from the outside world. Understanding this seemingly arcane process is important because dorsal closure uses molecular and cellular mechanisms very similar to those involved in wound-healing as well as those that can go awry in humans to produce the spinal malformation spina bifida.
The fouling of ships’ hulls, whether by barnacles and seaweed or by slime-creating bacteria, is a major problem for shipping worldwide, and particularly for navies. It has been estimated, for example, that fouling of hulls can create such turbulence as a ship moves through the water that fuel consumption is increased by as much as 30 percent. Traditionally major users of ships, like the U.S. Navy, have attempted to resist fouling by painting hulls with paints containing copper or triorganotin, a tin-based compound. But these paints are highly toxic and can leach into the water, killing marine life. That’s why their use increasingly is being prohibited. But help is at hand: A research group at Cornell University, Ithaca, N.Y., led by Christopher Ober, has developed two types of non-toxic paint, one hydrophilic and one hydrophobic, that effectively prevent fouling, whether by bacteria or barnacles. The paints act not only by minimizing adhesion by organisms but also by enabling hulls to become self-cleaning: As a ship moves through the water at 10 to 15 knots, the turbulence created removes the clinging barnacle or seaweed.
Researchers have identified a cell signaling system that may help the bacterium Pseudomonas aeruginosa establish itself in the lungs of cystic fibrosis patients. The researchers used a new technology to seek insights into an important and elusive enemy, and say the findings are important for biology and potentially important for therapy. The researchers identified the activation of this signaling system by the use of new quantitative proteomic technology that analyzed Pseudomonas samples from the lungs of children with cystic fibrosis. Proteomics is the method for analyzing and cataloguing a complete cellular complement of proteins, which are produced based on information encoded by genes and are the workhorses of all living cells.
Results of a new study show that breast sonography is more accurate than mammography in symptomatic women 45 years old or younger, and may be an appropriate initial imaging test in investigating these women, says Nehmat Houssami, MD, PhD, and lead author of the study. The study, published in the April 2003 issue of the American Journal of Roentgenology, “is the first published study to examine the comparative sensitivity and specificity of mammography and sonography in relation to age in young women with breast symptoms, where the two tests were interpreted independently of each other and where almost all subjects had undergone both tests,” says Dr. Houssami.
Research conducted by scientists at the Hebrew University of Jerusalem and the U.S. Department of Energy’s Brookhaven National Laboratory has paved the way for development of highly efficient sensors for measuring blood glucose in diabetic patients. Particles the size of a nanometer (that is, one billionth of a meter), which are the building blocks of the science of nanotechnology, have comparable dimensions to animal or plant proteins, thus enabling the integration of these components into hybrid systems exhibiting novel properties.