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Archive - Jan 1, 2015

Spectacular Finding: New Species of Fanged Frog Exhibits Rare Internal Fertilization and, Uniquely, Gives Birth to Live Tadpoles, This Latter Phenomenon Has NeverBeen Seen Before in Any Frog; The New Species Is Endemic to Indonesia’s Sulawesi Island

University of California (Berkeley) herpetologist Dr. Jim McGuire was slogging through the rain forests of Indonesia's Sulawesi Island one night this past summer when he grabbed what he thought was a male frog and found himself juggling not only a frog but also dozens of slippery, newborn tadpoles. He had found what he was looking for: direct proof that the female of a new species of frog does what no other frog does. It gives birth to live tadpoles instead of laying eggs. A member of the Asian group of fanged frogs, the new species was discovered a few decades ago by Indonesian researcher Dr. Djoko Iskandar, McGuire's colleague, and was thought to give direct birth to tadpoles, though the frog's mating and an actual birth had never been observed before. "Almost all frogs in the world - more than 6,000 species - have external fertilization, where the male grips the female in amplexus and releases sperm as the eggs are released by the female," Dr. McGuire said. "But there are lots of weird modifications to this standard mode of mating. This new frog is one of only 10 or 12 species that has evolved internal fertilization, and of those, it is the only one that gives birth to tadpoles as opposed to froglets or laying fertilized eggs." Dr. Iskander, Dr. McGuire and Dr. Ben Evans of McMaster University in Ontario, Canada, named the species Limnonectes larvaepartus and fully described it in an article published online on December 31, 2014 in the open-access journal PLOS ONE. Frogs have evolved an amazing variety of reproductive methods, says Dr. McGuire, an associate professor of integrative biology and curator of herpetology at UC Berkeley's Museum of Vertebrate Zoology. Most male frogs fertilize eggs after the female lays them.

Mayo Clinic Study Shows Atypical Breast Hyperplasia Poses Higher Risk of Breast Cancer Than Previously Thought; Risk Is 25% to 30% After 25 Years, Available Treatments Underutilized

Women with atypical hyperplasia of the breast have a higher risk of developing breast cancer than previously thought, a Mayo Clinic study has found. The authors note that measures to prevent the progression of atypical hyperplasia to cancer are available but underutilized. Results of the Mayo study, including work from colleagues at Vanderbilt University and the University of Virginia, appear in a special report on breast cancer published online on January 1, 2015 in the New England Journal of Medicine. Atypical hyperplasia of the breast is a precancerous condition found in about one-tenth of the over 1 million breast biopsies with benign findings performed annually in the United States. Viewed under a microscope, atypia contains breast cells that are beginning to grow out of control (hyperplasia) and cluster into abnormal patterns (atypical). Atypia lesions are considered benign, but by its risk and appearance and genetic changes, these lesions exhibit some of the early features of cancer. Data from hundreds of women with these benign lesions indicate that their absolute risk of developing breast cancer grows by over 1 percent a year. The study found that after five years, 7 percent of these women had developed the disease; after 10 years, that number had increased to 13 percent; and after 25 years, 30 percent had breast cancer. The finding places the more than 100,000 women diagnosed each year with atypical hyperplasia -- also known as atypia -- into a high-risk category, where they are more likely to benefit from intense screening and use of medications to reduce risk. "By providing better risk prediction for this group, we can tailor a woman's clinical care to her individual level of risk," says Lynn Hartmann, M.D., an oncologist at the Mayo Clinic and lead author of the study.