Syndicate content

Archive - Jun 14, 2011

Date
  • All
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30

Deadly Amphibian Disease Reaches Last Disease-Free Region in Central America

Smithsonian scientists have confirmed that chytridiomycosis, a rapidly spreading amphibian disease, has reached a site near Panama's Darien region. This was the last area in the entire mountainous neotropics to be free of the disease. This is troubling news for the Panama Amphibian Rescue and Conservation Project, a consortium of nine U.S. and Panamanian institutions that aims to rescue 20 species of frogs in imminent danger of extinction. Chytridiomycosis has been linked to dramatic population declines or even extinctions of amphibian species worldwide. Within five months of arriving at El Cope in western Panama, chytridiomychosis extirpated 50 percent of the frog species and 80 percent of individuals. "We would like to save all of the species in the Darien, but there isn't time to do that now," said Dr. Brian Gratwicke, biologist at the Smithsonian Conservation Biology Institute and international coordinator for the Panama Amphibian Rescue and Conservation Project. "Our project is one of a few to take an active stance against the probable extinction of these species. We have already succeeded in breeding three species in captivity. Time may be running out, but we are looking for more resources to take advantage of the time that remains." The Darien National Park is a World Heritage site and represents one of Central America's largest remaining wilderness areas. In 2007, Dr. Doug Woodhams, a research associate at the Smithsonian Tropical Research Institute, tested 49 frogs at a site bordering the Darien. At that time, none tested positive for the disease. In January 2010, however, Dr. Woodhams found that 2 percent of the 93 frogs he tested were infected. "Finding chytridiomycosis on frogs at a site bordering the Darien happened much sooner than anyone predicted," Dr.

New Type of Immune T-Cell Discovered

A team of Melbourne scientists has discovered a new type of cell in the immune system. The new cell type, a kind of white blood cell, belongs to a family of T-cells that play a critical role in protection against infectious disease. The team’s findings could ultimately lead to the development of novel drugs that strengthen the immune response against particular types of infectious organisms. It is also potentially significant for many other important diseases including allergies, cancer, and coronary artery disease. The research team includes Dr Adam Uldrich and Professor Dale Godfrey from the University of Melbourne, Dr Onisha Patel and Professor Jamie Rossjohn from Monash University and Professor Mark Smyth from the Peter MacCallum Cancer Institute. The discovery, published online on June 12, 2011, in the international journal Nature Immunology, represents a fundamental advance in understanding the different components of the immune system and how this system casts a net wide enough to catch all kinds of different infectious organisms. Typically, when the body is threatened with bacterial or viral infection, molecules called T-cell receptors interact with protein fragments (called peptides) from the bacterium or virus, triggering the immune response. This process has been widely studied and leads to the killing of microbes and protection against severe infection. While the immune system is known to focus on proteins from viruses and bacteria, some T-cells in the immune system (known as NKT cells) can recognize lipid-based, or fatty, molecules. As such, there is great enthusiasm for the potential of these lipid-sensing T-cells in the development of novel vaccines. This team has identified a new type of NKT cell that can specifically target lipids found in the cell walls of bacteria, including Mycobacteria.