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Young blood reverses heart decline in old mice
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Detlev van Ravenswaay/SPL
THE notion that Earth’s water was delivered by asteroids has taken a hit. Analysis of lunar rocks suggests that our planet was born wet, and was even able to give some water to the moon. Alberto Saal of Brown University in Providence, Rhode Island, and colleagues studied moon rocks brought back from the Apollo 17 mission in 1972. They looked at volcanic glasses inside the rocks, which were protected from weathering, to examine the ratio of hydrogen to its heavier isotope, deuterium. They found that the deuterium ratios were almost identical to those seen in earthly rock, suggesting the two worlds got their water from the same source (Science, doi.org/mg5). The moon probably formed after a massive collision between the infant Earth and another proto-planet about 4.5 billion years ago. Water could have been delivered to both bodies by asteroids, but it could have become mixed into lunar rock only if they hit while the moon was still molten after the impact that created it. Based on known impact rates, there would not have been time for enough asteroids to hit the moon before it cooled and solidified. That hints lunar water must have come from Earth, and that our planet had its water from the start, says Saal.
Pumping young blood rejuvenates the hearts of old mice WAS Dracula onto something? Pumping young blood around old bodies – at least in mice – can reverse cardiac hypertrophy, the thickening and swelling of the heart muscle that can come with age. The finding could lead to ways to treat the condition, a major cause of heart failure. Amy Wagers at Harvard University and her colleagues surgically joined the circulatory systems of pairs of mice: one a healthy 2-month-old animal, the other a 23-month-old with cardiac hypertrophy.
After just four weeks, the older mouse’s heart had reverted to almost the same size as its younger counterpart’s. “It was quite striking how the hearts responded… They were pretty much the same as in the young partner,” says Wagers. The hearts of the young mice were unaffected despite their pumping some blood from the older mice. Blood pressure also fell in the older mice as a result of the surgery, but the team’s tests ruled this out as a cause for the effect. Instead they focused on a protein
called GDF11, which was present in much higher quantities in the blood of the young mice. The researchers gave daily injections of GDF11 to old mice with cardiac hypertrophy. Thirty days later, their hearts were significantly smaller than those in a group of mice of the same age and with the same condition, but that had been injected with saline. Wagers suggests it could be worth giving low levels of GDF11 to people with cardiac hypertrophy. “We would hope that would result in similar effects,” she says. James Gerholdt/getty
Moon stole water from baby Earth
Better moth-eared than cloth-eared TALK about sharp hearing. The greater wax moth can hear ultrasonic sounds so high that they may not even exist in nature. During mating, male greater wax moths gather on trees and, shortly after sunset, start calling to females at frequencies way above the range of human ears. But the calls of their predators are higher still. The male moths call at 90 to 95 kilohertz, whereas bats echolocate their prey using sounds closer to 110 kilohertz, even hitting 212 kilohertz in some species. Evolution pushes the moths to keep up, so although they can’t produce calls at the same pitch as bats, they can hear them coming. Hannah Moir and colleagues at the University of Strathclyde in Glasgow, UK, tested the hearing of 20 adult greater wax moths and found that they could detect sounds up to 300 kilohertz (Biology Letters, doi.org/mgh). That’s higher than any known animal can produce. There are several possible explanations, says Moir. The bats could be producing higher frequencies than we can record, or the moths’ superb hearing could just be an evolutionary accident.
Don’t fear the reaper spider TINY but deadly. Of the 7000 people bitten every year in Brazil by brown recluse spiders, also known as reapers, 1.5 per cent die. There is an antivenom, but it can trigger side effects, and animals suffer so we can produce it. Now a Brazilian team has developed a synthetic version of the venom, allowing them to make a safer, kinder antidote. Normally, antivenom is made by injecting horses with spider venom to stimulate the production of antibodies. These are then extracted as a serum and given to bite victims. To make an alternative, Carlos
Chávez-Olórtegui of the Federal University of Minas Gerais and colleagues inserted genes into Escherichia coli. These genes code for surface features on the toxin that trigger antibody production. The bacteria then churned out a non-toxic, venom-like substance. When this was given to rabbits, the antibodies they made protected other rabbits against the spider venom almost as well as antibodies from horses exposed to the real thing (Vaccine, doi.org/mg3). The synthetic venom is free from impurities so any serum made from it should cause fewer side effects.
18 May 2013 | NewScientist | 15
Detlev van Ravenswaay/SPL
THE notion that Earth’s water was delivered by asteroids has taken a hit. Analysis of lunar rocks suggests that our planet was born wet, and was even able to give some water to the moon. Alberto Saal of Brown University in Providence, Rhode Island, and colleagues studied moon rocks brought back from the Apollo 17 mission in 1972. They looked at volcanic glasses inside the rocks, which were protected from weathering, to examine the ratio of hydrogen to its heavier isotope, deuterium. They found that the deuterium ratios were almost identical to those seen in earthly rock, suggesting the two worlds got their water from the same source (Science, doi.org/mg5). The moon probably formed after a massive collision between the infant Earth and another proto-planet about 4.5 billion years ago. Water could have been delivered to both bodies by asteroids, but it could have become mixed into lunar rock only if they hit while the moon was still molten after the impact that created it. Based on known impact rates, there would not have been time for enough asteroids to hit the moon before it cooled and solidified. That hints lunar water must have come from Earth, and that our planet had its water from the start, says Saal.
Pumping young blood rejuvenates the hearts of old mice WAS Dracula onto something? Pumping young blood around old bodies – at least in mice – can reverse cardiac hypertrophy, the thickening and swelling of the heart muscle that can come with age. The finding could lead to ways to treat the condition, a major cause of heart failure. Amy Wagers at Harvard University and her colleagues surgically joined the circulatory systems of pairs of mice: one a healthy 2-month-old animal, the other a 23-month-old with cardiac hypertrophy.
After just four weeks, the older mouse’s heart had reverted to almost the same size as its younger counterpart’s. “It was quite striking how the hearts responded… They were pretty much the same as in the young partner,” says Wagers. The hearts of the young mice were unaffected despite their pumping some blood from the older mice. Blood pressure also fell in the older mice as a result of the surgery, but the team’s tests ruled this out as a cause for the effect. Instead they focused on a protein
called GDF11, which was present in much higher quantities in the blood of the young mice. The researchers gave daily injections of GDF11 to old mice with cardiac hypertrophy. Thirty days later, their hearts were significantly smaller than those in a group of mice of the same age and with the same condition, but that had been injected with saline. Wagers suggests it could be worth giving low levels of GDF11 to people with cardiac hypertrophy. “We would hope that would result in similar effects,” she says. James Gerholdt/getty
Moon stole water from baby Earth
Better moth-eared than cloth-eared TALK about sharp hearing. The greater wax moth can hear ultrasonic sounds so high that they may not even exist in nature. During mating, male greater wax moths gather on trees and, shortly after sunset, start calling to females at frequencies way above the range of human ears. But the calls of their predators are higher still. The male moths call at 90 to 95 kilohertz, whereas bats echolocate their prey using sounds closer to 110 kilohertz, even hitting 212 kilohertz in some species. Evolution pushes the moths to keep up, so although they can’t produce calls at the same pitch as bats, they can hear them coming. Hannah Moir and colleagues at the University of Strathclyde in Glasgow, UK, tested the hearing of 20 adult greater wax moths and found that they could detect sounds up to 300 kilohertz (Biology Letters, doi.org/mgh). That’s higher than any known animal can produce. There are several possible explanations, says Moir. The bats could be producing higher frequencies than we can record, or the moths’ superb hearing could just be an evolutionary accident.
Don’t fear the reaper spider TINY but deadly. Of the 7000 people bitten every year in Brazil by brown recluse spiders, also known as reapers, 1.5 per cent die. There is an antivenom, but it can trigger side effects, and animals suffer so we can produce it. Now a Brazilian team has developed a synthetic version of the venom, allowing them to make a safer, kinder antidote. Normally, antivenom is made by injecting horses with spider venom to stimulate the production of antibodies. These are then extracted as a serum and given to bite victims. To make an alternative, Carlos
Chávez-Olórtegui of the Federal University of Minas Gerais and colleagues inserted genes into Escherichia coli. These genes code for surface features on the toxin that trigger antibody production. The bacteria then churned out a non-toxic, venom-like substance. When this was given to rabbits, the antibodies they made protected other rabbits against the spider venom almost as well as antibodies from horses exposed to the real thing (Vaccine, doi.org/mg3). The synthetic venom is free from impurities so any serum made from it should cause fewer side effects.
18 May 2013 | NewScientist | 15