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LONDON
(Reuters) - Researchers have discovered just how the malaria
parasite feasts on human blood cells in a breakthrough
that could lead to new treatments for the world"s most
dangerous tropical disease. Malaria kills more than a
million people each year and researchers now have a new
understanding about how the parasite survives and grows
in its human host.
The
scientists found that up to 2,000 pore-like holes on the
membranes of infected red blood cells provide the nutrients
needed for the hungry mosquito-borne parasite, plasmodium
flaciparum. Scientists at the U.S. National Institutes
of Health said the discovery of the so-called feeding
channels could lead to a new approach to combat the disease.
"It has been known for some 25 years that the parasites
increase uptake of certain nutrients but the mechanism
was not known," Dr Sanjay Desai said in a telephone interview.
"With this information, researches may be better able
to develop drugs to cut off the parasite"s nutrient supply."
The
malaria expert at the Laboratory of Parasitic Diseases
at the National Institute of Allergy and Infectious Disease
(NIAID) in Bethesda, Maryland, used a technique called
electrophysiology to find and study the channels, only
present on infected red blood cells. The holes are made
by specialised proteins that allow just the right nutrients
for the parasite to come through. Scientists are not sure
if the parasite changes a protein in the cell membrane
to create the channel or if it brings in a new protein
and incorporates it into the cell membrane. If a new protein
is added to the cell surface it could be a good target
for drugs designed to block the feeding channels and starve
the parasite to death.
IMPORTANT
STEP IN UNDERSTANDING MALARIA
Dr
Anthony Fauci, director of the NIAID, described the research
in the science journal Nature as a major achievement.
"This discovery is an important step forward in our understanding
of malaria and the search for new interventions to reduce
the burden of this devastating disease," he said in a
statement. Malaria is the most prevalent tropical disease
in the world with 300 to 500 million people being infected
each year. More than 40 percent of the world"s population
live in countries where malaria is endemic.
Ninety
percent of deaths from the illness occur in Africa. Two-thirds
of deaths are among children. Although drugs have been
available for decades to fight the disease, climate change,
social instability, increased travel and resistance to
pesticides and drugs have increased the death toll. The
disease causes high fever, muscle stiffness and sweating.
Cerebral malaria, the most dreaded form, results in death
within 24 hours. In addition to malaria, Desai said the
research, a collaboration with scientists from The National
Institute of Child Health and Development in Bethesda,
Maryland, could also have implications for other parasitic
diseases. "There is some evidence that other related parasites
use similar mechanisms," he said.
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