North Carolina
Between 1977 and 1996, portion sizes for key food groups grew markedly in the United States, not only at fast-food restaurants but also in homes and at conventional restaurants, a new study shows. The observation is one more indication of broad changes in the way Americans eat and another reason for the widespread, unhealthy rise in obesity among U.S. children and adults, University of North Carolina at Chapel Hill researchers say. It is believed to be the first documentation that at any given meal, on average, the typical American eats more than he or she did only a few decades ago.
Scientists have refined a technique that uses very intense light to determine the structure of chemically heterogeneous surfaces with a submillimeter resolution. The description of the technique and its application to the study of varying densities of surface-bound molecules - each about one thousand times smaller than the diameter of a human hair - appears as the cover story of the January 13, 2003, issue of Applied Physics Letters. "Surfaces with gradually varying structures are being investigated by academia and industry for their potential uses in creating cleaner energy sources, designing chemical and biological sensors, and creating molecular patterns," said Jan Genzer, a chemical engineer at North Carolina State University in Raleigh and the lead author of the study. "By determining the chemical structure of surfaces covered with films as thin as a few billionths of a meter, scientists and engineers can improve their properties and performance."
In an unusual disease known as Bloom syndrome, patients exhibit an extremely high incidence of cancers in many tissues. In fact, some experts consider Bloom syndrome to be among the most cancer-prone hereditary diseases known. Although the illness is rare, it fascinates scientists since it can teach them more about how cancers arise and how the body normally suppresses them. Information gleaned from studies of the syndrome should provide insights into other forms of cancer, they say. Now, working with fruit flies on the gene which, when mutated, causes Bloom syndrome in humans, scientists at the University of North Carolina at Chapel Hill have discovered more about the key mechanisms by which DNA inside cells is repaired.
Baby boomers will increase Medicare and other medical expenditures as they age but not nearly as much as some analysts have feared, according to a new study. The study, which appears in the January issue of the Journal of Gerontology, suggests that by living longer, many baby boomers will pass the ages at which the most "heroic," and hence expensive, efforts are made to prolong their lives. Once members of that generation survive into their mid-80s or so and beyond, many medical procedures will become too risky for their older bodies and will be avoided in many cases.
Spiny lobsters possess a remarkable navigational sense based on an ability to read small variations in the Earth's magnetic field, experiments conducted by North Carolina scientists show. The new work is the first to demonstrate that at least some invertebrate animals, which many people consider primitive underachievers biologically, possess navigational skills rivaling those of sea turtles and homing pigeons.
People troubled by the fact that the United States government has granted patents on genes and is likely to continue may find new hope through a legal argument being made by a North Carolina patent expert and a Philadelphia law student. Dr. John M. Conley and Dr. Roberte Makowski, a former agricultural biologist now studying law at Villanova University, say opponents of such patents have not taken advantage of the long-standing "product of nature" doctrine.
Researchers in North Carolina have successfully demonstrated that genetically altered stem cells from one species can be turned into a different sort of cell in another. Specifically, the researchers converted adult liver stem cells cloned from a male rat into functional adult bone marrow cells in female mice. The accomplishment, known as hematopoietic transdifferentiation, may prove useful for tapping the potential for tissue repair using human adult stem cells.
Breast cancer tumors that stop responding to the drug tamoxifen actually change their cellular characteristics and become responsive to other types of drugs, including Herceptin, according to oncologists at the Duke Comprehensive Cancer Center. "In the process of becoming resistant to tamoxifen, the tumors alter their qualities and become receptive to Herceptin and other drugs that target the HER-2 receptor," said Kimberly Blackwell, M.D., assistant professor of oncology at Duke.
Oncologists are testing a new technique called gene expression profiling that subtypes each breast cancer tumor by its genetic defects so that doctors can tailor their treatment to inhibit that particular tumor. The researchers believe the technique could spare millions of women from needlessly receiving toxic chemotherapy, and they are leading a national clinical trial to study gene profiling. "Currently, we have no predictive model to determine who will respond to hormonal therapies and who won't, so we prescribe chemotherapy as a backup measure to ensure the cancer's demise," said Matthew Ellis, M.D., Ph.D., director of the breast cancer program at Duke. "This one-treatment-fits-all approach leads to a huge amount of over treatment, with up to 50 percent of women unnecessarily receiving chemotherapy."
Researchers say they have found defects in the gene that produces a common protein in urine and that these defects are linked to two inherited kidney diseases. For six years, the researchers had studied a family from Western North Carolina that has been plagued with a rare kidney disease, trying to learn more about the genetics of the disease. The gene ordinarily produces a protein called either uromodulin or Tamm-Horsfall protein. Uromodulin is the most common protein released into the urine, but its function is unclear. Researchers identified mutations in the gene leading to defects in the protein. Defects in this protein led to a disease called familial juvenile hyperuricemic nephropathy.
In a new study, a microbiologist has discovered that the bacteria associated with almost all human ulcers - one that is also correlated with the development of certain types of gastric cancer in humans - uses hydrogen as an energy source. The finding is novel because most bacteria use sugars and other carbohydrates to grow, says Dr. Jonathan Olson, assistant professor of microbiology at North Carolina State. The human pathogen Helicobacter pylori does not.
If medical scientists sometimes find it hard to recruit enough volunteers -- especially blacks -- to participate in research studies, there may be a good reason, a new University of North Carolina at Chapel Hill study shows. A surprisingly high percentage of Americans asked -- almost 80 percent of blacks and 52 percent of whites -- were suspicious that they might be used as "guinea pigs" without their consent
Women who engage in vigorous leisure activity during their first and second trimesters of pregnancy may experience a decreased risk of preterm birth, a new study suggests. Vigorous leisure activity includes exercise programs such as swimming laps, jogging at a moderate to fast pace, aerobics or aerobic dance, other fast dancing and moderate to fast bicycling. Preterm birth is defined as delivery before completion of 37 weeks gestation.
Nicotine isn't all bad, despite its addictive qualities and its presence in tobacco products, increasingly taboo in these health-conscious times. As a chemical compound, nicotine even has beneficial properties. It's used around the world as a relatively cheap, environmentally friendly insecticide, repelling bugs that attack tobacco and other plants, and - contrary to popular misconceptions - it is not a carcinogen. Take a nicotine molecule and snip off a methyl group, though, and you've got nicotine's evil cousin: nornicotine.
A diet rich in flaxseed seems to reduce the size, aggressiveness and severity of tumors in mice that have been genetically engineered to develop prostate cancer, according to new research from Duke University Medical Center. And in 3 percent of the mice, the flaxseed diet kept them from getting the disease at all. "The amount of flaxseed given to each mouse was 5 percent of its total food intake, which would be a very difficult amount for humans to eat," said a lead researcher. "[B]ut it does signal that we are on the right track and need to continue research in this area."
