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US researchers say a malaria vaccine has shown promising results in early stage clinical trials.
Researchers found the vaccine protected 12 out of 15 patients from the disease, when given in high doses.
The method is unusual because it involves injecting live but weakened malaria-causing parasites directly into patients to trigger immunity.
The research is published in the journal Science.
Lead author Dr. Robert Seder, from the Vaccine Research Center at the National Institutes of Health, in Maryland, said: “We were excited and thrilled by the result, but it is important that we repeat it, extend it and do it in larger numbers.”
It has been known for several decades that exposure to mosquitoes treated with radiation can protect against malaria.
The new vaccine involves injecting live but weakened malaria-causing parasites directly into patients to trigger immunity
However, studies have shown that it takes more than 1,000 bites from the insects over time to build up a high level of immunity, making it an impractical method of widespread protection.
Instead, a biotech company called Sanaria has taken lab-grown mosquitoes, irradiated them and then extracted the malaria-causing parasite (Plasmodium falciparum), all under sterile conditions.
These living but weakened parasites are then counted and placed in vials, where they can then be injected directly into a patient’s bloodstream. This vaccine candidate is called PfSPZ.
To carry out the Phase-1 clinical trial, the researchers looked at a group of 57 volunteers, none of whom had had malaria before.
Of these, 40 received different doses of the vaccine, while 17 did not. They were then all exposed to the malaria-carrying mosquitoes.
The researchers found that for the participants not given any vaccine, and those given low doses, almost all became infected with malaria.
However for the small group given the highest dosage, only three of the 15 patients became infected after exposure to malaria.
Dr. Robert Seder said: “Based on the history, we knew dose was important because you needed 1,000 mosquito bites to get protection – this validates that.
“It allows us in future studies to increase the dose and alter the schedule of the vaccine to further optimize it. The next critical questions will be whether the vaccine is durable over a long period of time and can the vaccine protect against other strains of malaria.”
He added that the fact that the vaccine had to be injected into the bloodstream rather than into or under the skin made delivery more difficult.
There are currently about 20 malaria vaccine candidates in clinical trials.
The most advanced is called RTS,S/AS01, which has been developed by the pharmaceutical company GlaxoSmithKline, and is in a Phase-3 clinical trial involving 15,000 children in Africa.
According to the latest figures from the World Health Organization, there were an estimated 219 million cases of malaria in 2010 and an estimated 660,000 deaths.
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Scientists warn the H5N1 bird flu virus could change into a form able to spread rapidly between humans.
Researchers have identified five genetic changes that could allow the virus to start a deadly pandemic.
Writing in the journal Science, they say it would be theoretically possible for these changes to occur in nature.
A US agency has tried unsuccessfully to ban publication of parts of the research fearing it could be used by terrorists to create a bioweapon.
According to Prof. Ron Fouchier from the Erasmus Medical Centre in the Netherlands, who led the research, publication of the work in full will give the wider scientific community the best possible chance to combat future flu pandemics.
“We hope to learn which viruses can cause pandemics and by knowing that we might be able to prevent them by enforcing strict eradication programmes,” he said.
He added that his work might also speed the development of vaccines and anti-viral drugs against a lethal form of bird flu that could spread rapidly among people.
The H5N1 virus has been responsible for the deaths of tens of millions of birds and has led to hundreds of millions more being slaughtered to stop its spread.
The virus is also deadly to humans but can only be transmitted by close contact with infected birds.
Scientists warn the H5N1 bird flu virus could change into a form able to spread rapidly between humans
It is for this reason that relatively few people have died of bird flu. Latest World Health Organization (WHO) figures indicate 332 people have died of the illness since 2003.
Health officials are concerned though that the H5N1 virus could one day mutate into a form that could be spread between humans through coughs and sneezes through the air.
This could, they fear, result in a lethal pandemic that could spread rapidly across the world killing tens of millions of people.
It is only now that a study has confirmed that the emergence of such a deadly virus is theoretically possible.
A group led by Prof. Ron Fouchier wanted to find out which genetic changes were required to enable the H5N1 virus to mutate into a form that could be transmitted from person to person through the air.
His team compared the genetic structure of the bird flu virus with those responsible for earlier human flu pandemics.
The researchers found five key differences, which they reasoned could be the mutations required for airborne transmission of the virus.
They confirmed their theory was correct by genetically engineering those changes into the H5N1 virus which they found could then be spread between ferrets through coughing and sneezing.
A team from Cambridge University then looked to see whether such a mutation could emerge naturally and if so its likelihood.
The researchers studied the genetic structure of 3,000 bird viruses and 400 that occur in humans.
They found some of these viruses had two of the key changes needed to become airborne. Mathematical modeling suggested it was indeed possible for a virus to develop the three further changes required during the course of an epidemic.
It is the first time it has been shown that it is possible for bird flu to become airborne, but the research team was unable to determine precisely how likely this was to happen.
Prof. Derek Smith, who led the analysis, said more information was needed.
He said researchers required a better understanding of how flu viruses were transmitted between people in order to develop a clearer idea of the likelihood of the emergence of an airborne strain of bird flu.
“These are difficult things to find out,” said Prof. Derek Smith.
“What this work enables us to do is to prioritize particular experiments to obtain this information.”
It is clear though that the emergence of an airborne mutation of H5N1 is unlikely. Were it not it would have emerged already.
But researchers want to be able to calculate the risk of such a virus emerging more precisely in order to help public health officials in their contingency planning.
News of Prof. Ron Fouchier’s work, and another similar study by Yoshihiro Kawaoka published this May in the journal Nature, prompted the US National Security Advisory Board for Biotechnology (NSABB) to ask both journals last November to redact some sensitive parts of the research.
The NSABB believed the information could be used by terrorists to create a bioweapon.
The scientists who carried out the research, and the journals concerned, considered suggestions as to how the results could be redacted in the journals, but distributed to bona fide researchers who urgently needed the information.
But they concluded such a system was unworkable.
“You can’t share information with so many people in the field and keep it confidential,” according to Prof. Ron Fouchier.
Editor in chief of the journal Science, Dr. Bruce Alberts, said the publication of the research in both Science and Nature had “shone a spotlight” on the need to deal more effectively with research that could be misused by terrorists – so called “dual use research of concern” (DURC).
“It has become clear that we will need to work toward the establishment of a comprehensive, international system for assessing DURC, one that includes transparent procedures to allow selected access to any information omitted from a scientific publication to those with a need to know.”
But Prof. Ron Fouchier questioned whether a system of asking scientific journals to censor DURC work is ever workable or even appropriate.
“The general mode should be that science should be freely available so that the wider scientific community can build on the research,” he said.
“I have a hard time identifying research papers that you shouldn’t publish. So I’m not sure whether we should ever go down this alley.”
Researchers have found that red dots, hand stencils and animal figures represent the oldest examples yet found of cave art in Europe.
The symbols on the walls at 11 Spanish locations, including the World Heritage sites of Altamira, El Castillo and Tito Bustillo have long been recognized for their antiquity.
But researchers have now used refined dating techniques to get a more accurate determination of their ages.
One motif – a faint red dot – is said to be more than 40,000 years old.
“In Cantabria, [in] El Castillo, we find hand stencils that are formed by blowing paint against the hands pressed against the wall of a cave,” explained Dr. Alistair Pike from Bristol University, UK, and the lead author on a scholarly paper published in the journal Science.
“We find one of these to date older than 37,300 years on <<The Panel of Hands>>, and very nearby there is a red disc made by a very similar technique that dates to older than 40,800 years.
“This now currently is Europe’s oldest dated art by at least 4,000 years,” he told reporters.
Researchers have found that red dots, hand stencils and animal figures represent the oldest examples yet found of cave art in Europe
It is arguably also the oldest reliably dated cave art anywhere in the world.
The team arrived at the ages by examining the calcium carbonate (calcite) crusts that had formed on top of the paintings.
This material builds up in the exact same way that stalagmites and stalactites form in a cave.
In the process, the calcite incorporates small numbers of naturally occurring radioactive uranium atoms. These atoms decay into thorium at a very precise rate through the ages, and the ratio of the two different elements in any sample can therefore be used as a kind of clock to time the moment when the calcite crust first formed.
Uranium-thorium dating has been around for decades, but the technique has now been so refined that only a tiny sample is required to get a good result.
This enabled the team to take very thin films of deposits from just above the paint pigments; and because the films were on top, the dates they gave were minimum ages – that is, the paintings had to be at least as old as the calcite deposits, and very probably quite a bit older.
The oldest dates coincide with the first known immigration into Europe of modern humans (Homo sapiens). Before about 41,000 years ago, it is their evolutionary cousins, the Neanderthals (Homo neanderthalensis), who dominate the continent.
Dr. Alistair Pike’s and colleagues’ work therefore raises some intriguing questions about who might have authored the markings.
If anatomically modern humans were responsible then it means they engaged in the activity almost immediately on their arrival in Europe.
If Neanderthals were the artisans, it adds another layer to our understanding of their capabilities and sophistication.
The great antiquity of the paintings leads co-author Joao Zilhao, a research professor at ICREA, University of Barcelona, to think the Neanderthals produced the motifs. Finding even older paintings than the red dot at El Castillo might confirm that “gut feeling”, he said.
“There is a strong chance that these results imply Neanderthal authorship,” Prof. Joao Zilhao explained.
“But I will not say we have proven it because we haven’t, and it cannot be proven at this time.
“What we have to do now is go back, sample more and find out whether we can indeed get dates older than 42, 43, 44,000.
“There is already a sampling programme going on. We have samples from more sites in Spain, from sites in Portugal and from other caves in Western Europe and so eventually we will be able to sort it out.”
Tracing the origins of abstract throught and behaviors, and the rate at which they developed, are critical to understanding the human story.
The use of symbolism – the ability to let one thing represent another in the mind – is one of those traits that set our animal species apart from all others.
It is what underpins artistic endeavor and also the use of language.
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Parasitic Varroa mite has helped a virus wipe out billions of honeybees throughout the globe, say scientists.
A team studying honeybees in Hawaii found that the Varroa mite helped spread a particularly nasty strain of a disease called deformed wing virus.
The mites act as tiny incubators of one deadly form of the disease, and inject it directly into the bees’ blood.
This has led to “one of the most widely-distributed and contagious insect viruses on the planet”.
The findings are reported in the journal Science.
A team studying honeybees in Hawaii found that the Varroa mite helped spread a particularly nasty strain of a disease called deformed wing virus
The team, led by Dr. Stephen Martin from the University of Sheffield, studied the honeybees in Hawaii, where Varroa was accidentally brought from California just five years ago.
Crucially some Hawaiian islands have honeybee colonies that are still Varroa-free.
This provided the team with a unique natural laboratory; they could compare recently-infected colonies with those free from the parasite, and paint a biological picture of exactly how Varroa affected the bees.
The team spent two years monitoring colonies – screening Varroa-infected and uninfected bees to see what viruses lived in their bodies.
Dr. Stephen Martin explained that most viruses were not normally harmful to the bees, but the mite “selected” one lethal strain of one specific virus.
“In an infected bee there can be more viral particles than there are people on the planet,” he explained.
“There’s a vast diversity of viral strains within a bee, and most of them are adapted to exist in their own little bit of the insect; they get on quite happily.”
But the mite, he explained, “shifts something”.
In Varroa-infected bees, over time, the vast majority of these innocuous virus strains disappear and the bees’ bodies are filled with one lethal strain of deformed wing virus.
And when it comes to viral infection, it’s the sheer quantity that kills; each viral particle invades a cell and takes over its internal machinery, turning the bee’s own body against itself.
Although it is not clear exactly why this strain thrives in mite-infected bees, Dr. Stepehn Martin explained that it could be the one virus best able to survive being repeatedly transmitted from the mites to the bees and back, as the mites feed on the bees’ blood.
The effect appears to take once the mites have changed this “viral landscape” in the bees’ bodies, the change is permanent.
“So the only way to control the virus is to control the levels of the mite,” said Dr. Stephen Martin.
Researchers at the University of Washington have found that Greenland’s glaciers are losing less ice than scientists once feared.
The loss of ice from the glaciers that cover the island is still about 30% faster than it was a decade ago, said researchers the University of Washington.
That means Greenland’s contribution to future sea level rise would be about 4 inches by the year 2100 if ice loss does not speed up much more, a study author said.
That may not sound like much, but when other causes of sea rise around the globe are added, the total could still be about three feet by the end of the century, researchers said.
“<<Glacial pace>> is not slow anymore,” said study author Twila Moon, a glacier researcher at the University of Washington.
Researchers at the University of Washington have found that Greenland's glaciers are losing less ice than scientists once feared
At the same time, “some of the worst-case possibilities that we had imagined are not coming true at this point” Twila Moon said.
“So it’s not good news, but it’s not bad news.”
The scientists relied on a comprehensive satellite-based survey of about 200 glaciers to make their calculations. Their research was published yesterday in the journal Science.
Compared to some past research the findings are somewhat reassuring. A 2008 study had suggested a worst-case scenario that indicated Greenland’s glaciers might contribute up to 19 inches of sea rise by the end of the century.
The glaciers have been melting under warmer summer temperatures in Greenland that on average are up by about two degrees Fahrenheit (one degree Celsius) over the last decade, study authors said.
One famous glacier on northwestern Greenland called Jakobshavn is now losing ice at a particularly fast pace of seven miles (11.3 km) per year. That means an ice loss of nearly 3 feet (one metre) of ice every hour. If you stare at the glacier for about 20 minutes you can notice it move, said University of California Irvine glacier expert Eric Rignot.
Even so, that pace does not match the predictions laid out in the worst-case laid out in the 2008 study, research that caused alarm about the effects of increasing greenhouse gas emissions that warm the earth.
“We’re not seeing kind of runaway effects,” said study co-author, Ian Joughin.
Eric Rignot said it is unfair to compare this recent study to the more alarming 2008 one, which he said was not designed to be overly realistic. However, he noted that the findings of this new study still exceed computer models and projections by the Nobel Prize-winning Intergovernmental Panel on Climate Change.
NASA Chief Scientist Waleed Abdalati, an ice scientist, called the new work a “valuable study that advances our understanding of a very complex wild card of sea level rise”.
Scientists at the University of Cambridge suggest that abnormalities in the brain may make some people more likely to become drug addicts.
The researchers found the same differences in the brains of addicts and their non-addicted brothers and sisters.
The study, published in the journal Science, suggested addiction is in part a “disorder of the brain”.
Other experts said the non-addicted siblings offered hope of new ways of teaching addicts “self-control”.
It has long been established that the brains of drug addicts have some differences to other people, but explaining that finding has been more difficult.
Scientists were unsure whether drugs changed the wiring of the brain or if drug addicts’ brains were wired differently in the first place.
This study, funded by the Medical Research Council, attempted to answer that by comparing the brains of 50 cocaine or crack addicts with the brain of their brother or sister, who had always been clean.
Both the addicts and the non-addict siblings had the same abnormalities in the region of the brain which controls behavior, the fronto-striatal systems.
The suggestion is that these brains may be “hard-wired” for addiction in the first place.
Lead researcher Dr. Karen Ersche said: “It has long been known that not everyone who takes drugs becomes addicted.
“It shows that drug addiction is not a choice of lifestyle, it is a disorder of the brain and we need to recognize this.”
However, the non-addicted siblings had a very different life despite sharing the same susceptibility.
“These brothers and sisters who don’t have addiction problems, what they can tell us is how they overcome these problems, how they manage self-control in their daily life,” Dr. Karen Ersche said.
Dr. Paul Keedwell, a consultant psychiatrist at Cardiff University, said: “Addiction, like most psychiatric disorders, is the product of nature and nurture.
“We need to follow up people over time to quantify the relative risk of nature versus nurture.”
It is possible that the similarities in the sibling’s brains may not be down to genetics, but rather growing up in the same household. Research on the relationship between addiction and the structure of the brain is far from over.
However, many specialists believe these findings open up new avenues for treatment.
“If we could get a handle on what makes unaffected relatives of addicts so resilient we might be able to prevent a lot of addiction from taking hold,” said Dr. Paul Keedwell.
The chief pharmacist for Derbyshire Mental Health Trust, David Branford, said the study, “implies that addiction does not produce noticeable changes to brain structure and function which means that there may be provision for looking at new treatment techniques for addiction”.
Prof. Les Iversen, from the department of pharmacology at the University of Oxford, said: “These new findings reinforce the view that the propensity to addiction is dependent on inherited differences in brain circuitry, and offer the possibility of new ways of treating high-risk individuals to develop better <<self control>>.”
