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Archive - Mar 20, 2013

New Imaging Agent Enables Better Cancer Detection, More Accurate Staging

Researchers at the University of California (UC), San Diego School of Medicine have shown that a new imaging dye, designed and developed at the UC San Diego Moores Cancer Center, is an effective agent in detecting and mapping cancers that have reached the lymph nodes. The radioactive dye called Technetium Tc-99m tilmanocept, successfully identified cancerous lymph nodes and did a better job of marking cancers than the current standard dye. Results of the Phase III clinical trial were published online on March 20, 2013 in the Annals of Surgical Oncology. "Tilmanocept is a novel engineered radiopharmaceutical specifically designed for sentinel lymph node detection," said David R. Vera, Ph.D., the drug's inventor, who is a professor in the UCSD Department of Radiology. "The molecule, developed at UC San Diego School of Medicine, offers surgeons a new tool to accurately detect and stage melanoma and breast cancers while in the operating room." On March 13, 2013, tilmanocept received U.S. Food and Drug Administration (FDA) approval. After a cancer diagnosis, surgeons want to be sure that the disease has not spread to a patient's lymph nodes, especially the sentinel nodes that may be the first place that a cancer reaches. The lymphatic system is a network of vessels and ducts that carry disease-fighting cells throughout the body, but can also act as a way for cancer cells to access the bloodstream. By surgically removing and examining the sentinel nodes that drain a tumor, doctors can better determine if a cancer has spread. "Tilmanocept advances the molecular targeting in breast cancer.

Baffling Rare Blood Type (Vel-Negative) Finally Explained

In the early 1950’s, a 66-year-old woman, sick with colon cancer, received a blood transfusion. Then, unexpectedly, she suffered a severe rejection of the transfused blood. Reporting on her case, the French medical journal Revue D’Hématologie identified her as, simply, “Patient Vel.” After a previous transfusion, it turns out, Mrs. Vel had developed a potent antibody against some unknown molecule found on the red blood cells of most people in the world—but not found on her own red blood cells. But what was this molecule? Nobody could find it. A blood mystery began, and, from her case, a new blood type, “Vel-negative,” was described in 1952. Soon it was discovered that Mrs. Vel was not alone. Though rare, it is estimated now that over 200,000 people in Europe and a similar number in North America are Vel-negative, about 1 in 2,500. For these people, successive blood transfusions could easily turn to kidney failure and death. So, for sixty years, doctors and researchers have hunted—unsuccessfully—for the underlying cause of this blood type. But now a team of scientists from the University of Vermont (UVM) and France has found the missing molecule—a tiny protein called SMIM1—and the mystery is solved. Reporting in the journal EMBO Molecular Medicine, UVM’s Dr. Bryan Ballif, Dr. Lionel Arnaud of the French National Institute of Blood Transfusion, and their colleagues explain how they uncovered the biochemical and genetic basis of Vel-negative blood. “Our findings promise to provide immediate assistance to health-care professionals should they encounter this rare but vexing blood type,” says Dr. Ballif. The pre-publication results were presented online on March 18, 2013, and the finalized report will be published, as an open-access article, in the next edition of the journal. Last year, Drs.

Plants Recognize and Respond Specifically to Predators

Insect or microbe: plants recognize their attackers and respond by producing specific internal signals that induce the appropriate chemical defenses. That is the main conclusion of a study at the Center for Medical, Agricultural and Veterinary Entomology operated in Gainesville, Florida (USA) by the USDA’s Agricultural Research Service, to which the team around Professor Ted Turlings of the University of Neuchâtel, Switzerland, has contributed. The study was published online on March 18, 2013 in PNAS. When attacked, plants produce cascades of molecular reactions aimed at neutralizing their specific opponents. In response to insect attack plants produce toxins that directly affect the herbivore, but they also emit an odorous cry for help that attracts natural enemies of the pest, thus ensuring indirect protection of the plants. However, the biochemical mechanisms which trigger these defenses have been poorly understood until now. The research to which the biologists of the University of Neuchâtel contributed is directed precisely at this missing link. It has led to the identification of a peptide called ZmPep3, which maize plants produce when their leaves are eaten by herbivorous caterpillars. This peptide triggers the production of insecticidal substances, as well as the emission of a particular odor that specifically attracts natural enemies of the pest, in this case a parasitic wasp that lays its eggs in the caterpillars. To determine the attractiveness of odorous signals, the Gainesville team turned to the Neuchâtel group of experts, known for their discovery of the cry for help in plants.