Calorie listings don’t encourage overeating, study says
Labeling foods “low-fat” is suspected of encouraging consumers to overeat. If that box of Ho-Ho’s claims to be low-fat, heck, why not down the full dozen? But a study from Penn State says the same is not true of the listing of caloric content. “Some studies have shown that people take larger portions of foods labeled ‘low fat’ ? using the label as a license to eat more. This study shows that energy density labels are unlikely to undermine the benefits of offering foods with fewer calories per ounce.”
This is a little complex, but bear with us. Nearly all cells house their DNA inside a nucleus. But a little one-celled critter called Tetrahymena houses different versions of its DNA in each of its two nuclei. Researchers have found that the smaller nucleus (called the micronucleus) just keeps the cell’s full genome safe, acting as a sort of “lock box.” The larger nucleus (called the macronucleus) uses the DNA to regulate the cell’s life functions. When the cell mates to create a new generation, the two work together to compare the cell’s current DNA against what’s been stored in the lock box. If any foreign genes have snuck in (like from a virus) they nuclei eliminate it, to make sure baby gets a fresh start. Pretty neat, with possible implications for larger organisms, too.
Using neural stem cells to hunt down and kill cancer cells, researchers have successfully tested a new treatment for brain cancer. They now hope the technique will lead to an effective treatment for glioma, the most aggressive form of primary brain tumor in humans. As the Cedars-Sianai researchers note, the prognosis has historically been extremely poor for patients diagnosed with malignant gliomas. The tumors have poorly defined margins, and glioma cells often spread deep into healthy brain tissue making their surgical removal difficult. Often, pockets of tumor cells break off from the main tumor and migrate deep into non-tumorous areas of the brain. Therefore, even if the original tumor is completely removed or destroyed, the risk of recurrence is high as cells in these distant “satellites” multiply and eventually re-form a new brain tumor. Due to these characteristics, treating brain cancer has been extremely difficult.
Researchers say they’ve successfully tracked a star racing around a dark mass at the center of our Milky Way galaxy, offering strong support for the theory that a black hole is at the center of our little corner of space. Astronomers at the Max Planck Institute for Astrophysics tracked the orbit of the closest known star to the black hole candidate Sagittarius A*, a dark mass 3,000,000 times the mass of the sun. Following the star for 10 years, they found that it does indeed orbit Sagittarius A*. Approaching the black hole’s maw, the star reaches its highest velocity, whizzing past it at 5,000 kilometers per second.
Men who test positive for elevated prostate specific antigen (PSA) levels sometimes freak out because they think it means they have cancer. To find out, a surgeon will often perform a biopsy. But researchers from the National Cancer Institute and the Food and Drug Administration report that a new test using a single drop of blood could help distinguish between prostate cancer and benign conditions. The trick is identifying patterns of proteins found in patients’ blood serum.
Researchers have found that plant-eating insects use a form of molecular code-breaking to protect themselves against repellants employed by their dinner. Scientists in Illinois have detailed how corn earworms (Helicoverpa zea) intercept defensive chemical signals used by their hosts and then produce detoxifying agents to partially counter the threat against them.