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Malaria's weakest link
Research news and discovery
MICHEL RENAUDEAU/HOA-QUI/CAMERAPRESS
In brief– Key to malaria
Aztecs grew sunflowers long before the Spanish arrived FARMERS in ancient Mexico were not only clued up on cultivating maize, peppers and cotton – it seems they were the first to grow sunflowers too. “Conventional wisdom is that sunflowers were cultivated in eastern North America,” says David Lentz at the University of Cincinnati in Ohio. The crop was thought to have been introduced to Mexico by the Spanish conquistadors in the 16th century. So, when Lentz discovered domesticated sunflower seeds in a 4100-year-old Mexican archaeological site in 2001, sceptics dismissed the find as an aberration.
Now Lentz’s team has unearthed further evidence that the sunflower has an ancient cultural history in the area. If it had been introduced by the Spanish, Lentz argues it would be known across Mexico by the Spanish name for “sunflower”. Instead, his team found 11 of 14 indigenous Mexican groups each had a unique name for the plant. Lentz also found references to “sunflower” in the Florentine Codex, an account of Aztec culture written just before the Spanish conquest. It shows that the sunflower had symbolic links with Mexican religion and nobility. Rather than introduce the flower to the area, Lentz thinks the Spanish suppressed sunflower farming as they imposed their authority on Mexico (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0711760105).
An ACE way to fight the flab IT SOUNDS like the perfect remedy for modern life: a pill that simultaneously reduces both belly fat and blood pressure. And it may already exist. High blood pressure is often treated with drugs called ACE inhibitors, which block angiotensin-converting enzyme (ACE). ACE usually constricts blood vessels and so raises blood pressure. It is also expressed in fat 16 | NewScientist | 3 May 2008
cells, and previous studies had suggested that it might trigger fat accumulation. To investigate exactly what ACE does, Michael Mathai of the Howard Florey Institute in Melbourne, Australia, and colleagues engineered mice to lack the ACE gene. These mice turned out to weigh 20 per cent less than normal mice and had 50 to 60 per cent less body fat, especially in the
abdomen. The mice also cleared excess sugar from the blood faster, making them less prone to diabetes (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0802690105). This suggests that mice lacking ACE can burn off excess energy without skimping on food or being more physically active. ACE “seems to increase fat storage and the creation of new fat cells”, says Mathai, adding that ACE inhibitors might therefore help people lose weight.
MALARIA parasites kill a million people a year, by infecting their red blood cells and gobbling up the haemoglobin proteins that transport oxygen in the blood. But the “haem” portion of haemoglobin is toxic and, to avoid destruction, the Plasmodium parasite turns it into a non-toxic crystal called haemozoin. Several existing malaria drugs work by binding to haem and stopping its transformation. However, understanding the process better could lead to the development of desperately needed new drugs for malaria. Now Dewal Jani and his colleagues at Virginia Tech in Blacksburg have identified the key enzyme used by the parasite – called HDP. Mass screening has also identified several chemicals that might inhibit HDP, which is conserved across all Plasmodium species they tested (PLoS Pathogens, DOI: 10.1371/journal. ppat.1000053).
Hey aliens, we’re over here NO MATTER how quiet we try to be now it’s too late to prevent alien invaders. So says Alexander Zaitsev of the Institute of Radio Engineering and Electronics in Moscow, Russia, who points the finger at astronomers. For 40 years, astronomers have fired microwaves off objects to chart near-Earth space and track the movement of close asteroids – and these signals are traceable back to us. By comparison, Zaitsev says, dedicated transmissions – often described as “shouting into an unknown jungle” – are a mere whisper. He calculates the astronomy signals have filled an area of the sky 2000 times greater than dedicated broadcasts have managed to date (www.arxiv. org/0804.2754). www.newscientist.com
MICHEL RENAUDEAU/HOA-QUI/CAMERAPRESS
In brief– Key to malaria
Aztecs grew sunflowers long before the Spanish arrived FARMERS in ancient Mexico were not only clued up on cultivating maize, peppers and cotton – it seems they were the first to grow sunflowers too. “Conventional wisdom is that sunflowers were cultivated in eastern North America,” says David Lentz at the University of Cincinnati in Ohio. The crop was thought to have been introduced to Mexico by the Spanish conquistadors in the 16th century. So, when Lentz discovered domesticated sunflower seeds in a 4100-year-old Mexican archaeological site in 2001, sceptics dismissed the find as an aberration.
Now Lentz’s team has unearthed further evidence that the sunflower has an ancient cultural history in the area. If it had been introduced by the Spanish, Lentz argues it would be known across Mexico by the Spanish name for “sunflower”. Instead, his team found 11 of 14 indigenous Mexican groups each had a unique name for the plant. Lentz also found references to “sunflower” in the Florentine Codex, an account of Aztec culture written just before the Spanish conquest. It shows that the sunflower had symbolic links with Mexican religion and nobility. Rather than introduce the flower to the area, Lentz thinks the Spanish suppressed sunflower farming as they imposed their authority on Mexico (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0711760105).
An ACE way to fight the flab IT SOUNDS like the perfect remedy for modern life: a pill that simultaneously reduces both belly fat and blood pressure. And it may already exist. High blood pressure is often treated with drugs called ACE inhibitors, which block angiotensin-converting enzyme (ACE). ACE usually constricts blood vessels and so raises blood pressure. It is also expressed in fat 16 | NewScientist | 3 May 2008
cells, and previous studies had suggested that it might trigger fat accumulation. To investigate exactly what ACE does, Michael Mathai of the Howard Florey Institute in Melbourne, Australia, and colleagues engineered mice to lack the ACE gene. These mice turned out to weigh 20 per cent less than normal mice and had 50 to 60 per cent less body fat, especially in the
abdomen. The mice also cleared excess sugar from the blood faster, making them less prone to diabetes (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0802690105). This suggests that mice lacking ACE can burn off excess energy without skimping on food or being more physically active. ACE “seems to increase fat storage and the creation of new fat cells”, says Mathai, adding that ACE inhibitors might therefore help people lose weight.
MALARIA parasites kill a million people a year, by infecting their red blood cells and gobbling up the haemoglobin proteins that transport oxygen in the blood. But the “haem” portion of haemoglobin is toxic and, to avoid destruction, the Plasmodium parasite turns it into a non-toxic crystal called haemozoin. Several existing malaria drugs work by binding to haem and stopping its transformation. However, understanding the process better could lead to the development of desperately needed new drugs for malaria. Now Dewal Jani and his colleagues at Virginia Tech in Blacksburg have identified the key enzyme used by the parasite – called HDP. Mass screening has also identified several chemicals that might inhibit HDP, which is conserved across all Plasmodium species they tested (PLoS Pathogens, DOI: 10.1371/journal. ppat.1000053).
Hey aliens, we’re over here NO MATTER how quiet we try to be now it’s too late to prevent alien invaders. So says Alexander Zaitsev of the Institute of Radio Engineering and Electronics in Moscow, Russia, who points the finger at astronomers. For 40 years, astronomers have fired microwaves off objects to chart near-Earth space and track the movement of close asteroids – and these signals are traceable back to us. By comparison, Zaitsev says, dedicated transmissions – often described as “shouting into an unknown jungle” – are a mere whisper. He calculates the astronomy signals have filled an area of the sky 2000 times greater than dedicated broadcasts have managed to date (www.arxiv. org/0804.2754). www.newscientist.com