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Archive - Oct 18, 2011

Two New Bee Species May Shed Light on Panama’s History

Smithsonian scientists have discovered two new, closely related bee species: one from Coiba Island in Panama and another from northern Colombia. Both descended from of a group of stingless bees that originated in the Amazon and moved into Central America, the ancestors of Mayan honeybees. The presence of one of these new species on Coiba and Rancheria Islands, and its absence from the nearby mainland, is a mystery that may ultimately shed light on Panama's history and abundant biodiversity. The new findings were published online on September 8, 2011 in Systematic Entomology. At almost 200 square miles, Coiba Island is the largest offshore island along the Pacific coast of Latin America. Rancheria Island is a much smaller neighbor. The species name, insularis, of the new bee from Coiba, Melipona insularis, means "island." This is the first species in its group to be found on islands near the mainland. "These forest bees have a small range over which they can establish new nests and colonies," says Dr. David Roubik, staff scientist at the Smithsonian Tropical Research Institute. "They can't establish a new nest across more than a short stretch of open water because workers from the original nest have to build and supply the new nest before the new queen moves in." Either several entire tree-cavity nests arrived on Coiba and Rancheria in floating mats of vegetation or a land connection existed between the island and the mainland before the bees disappeared from the mainland. Sea level has risen and fallen dramatically in the past. During ice ages, when much of the Earth's water is locked up in polar caps and glaciers, sea level drops in Panama.

First Phase III Results Suggest Promise of New Malaria Vaccine

First results from a large-scale Phase III trial of RTS,S, published online on October 18, 2011 in the New England Journal of Medicine (NEJM), show the malaria vaccine candidate to provide young African children with significant protection against clinical and severe malaria with an acceptable safety and tolerability profile. The results were announced today at the Malaria Forum hosted by the Bill & Melinda Gates Foundation in Seattle, Washington. Half the world's population is at risk of malaria. The disease is responsible for close to 800,000 deaths each year, most of whom are children under five in sub-Saharan Africa The trial, conducted at eleven trial sites in seven countries across sub-Saharan Africa, including a University of North Carolina-led site in Lilongwe, Malawi, showed that three doses of RTS,S reduced the risk of children experiencing clinical malaria and severe malaria by 56 percent and 47 percent, respectively. This analysis was performed on data from the first 6,000 children aged 5 months to 17 months, over a 12-month period following vaccination. Clinical malaria results in high fevers and chills. It can rapidly develop into severe malaria, typified by serious effects on the blood, brain, or kidneys that can prove fatal. These first Phase III results are in line with those from previous Phase II studies. The widespread coverage of insecticide-treated bed nets (75 percent) in this study indicated that RTS,S can provide protection in addition to that already offered by existing malaria control interventions. The trial is ongoing and efficacy and safety results in 6 week- old to 12 week-old infants are expected by the end of 2012. These data will provide an understanding of the efficacy profile of the RTS,S malaria vaccine candidate in this age group, for both clinical and severe malaria.

First-Ever Sequence of a Particular Biologically Important Complex Carbohydrate

If genes provide the blueprint for life and proteins are the machines that do much of the work for cells, then carbohydrates that are linked to proteins are among the tools that enable cells to communicate with the outside world and each other. But until now, scientists have been unable to determine the structure of a biologically important so-called GAG proteoglycan-or even to agree whether these remarkably complex molecules have well-defined structures. In a paper published online on October 9, 2011 in the journal Nature Chemical Biology, however, a team of scientists from the University of Georgia (UGA), Rensselaer Polytechnic Institute, and Chiba University in Japan announced that it has, for the first time, determined the sequence and structure of a glycosaminoglycan, or GAG, proteoglycan. "The fact that a structure even exists is surprising, because people had the sense that the complexity of these molecules pointed to a randomness," said study co-author Dr. Jonathan Amster, professor and head of the department of chemistry in the UGA Franklin College of Arts and Sciences. "There are many different areas in medicine that will be enabled by understanding carbohydrates at this fundamental level." Modifications to the GAG, or carbohydrate biopolymer, portion of proteoglycans have been associated with the presence and malignancy of certain cancers, for example, and the researchers noted that the identification of carbohydrates that are involved in disease opens the door to the development of drugs that can block their action. The field of glycobiology is still in its infancy, largely because attempts to sequence proteoglycans have, until now, ended in frustration and failure.