Archive for the ‘Science’ Category
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LONDON (Reuters) – Is nanomedicine the next big thing? A growing number of top drug companies seem to think so.
The ability to encapsulate potent drugs in tiny particles measuring billionths of a meter in diameter is opening up new options for super-accurate drug delivery, increasing precision hits at the site of disease with, hopefully, fewer side effects.
Three deals struck this year by privately held Bind Therapeutics, together worth nearly $1 billion if experiments are successful, highlight a new interest in using such tiny carriers to deliver drug payloads to specific locations in the body.
U.S.-based Bind is one of several biotechnology firms that are luring large pharmaceutical makers with a range of smart drug nanotechnologies, notably against cancer.
And nanomedicine is also being put to work in diagnosis, with tiny particles used to improve imaging in scanners, as well as rapidly detecting some serious infections.
In future, researchers hope to combine both treatment and diagnostics in a new approach dubbed “theranostics” that would allow doctors to monitor patients via their medicines.
After much hype but limited clinical success, scientists in the nanotechnology field finally see a turning point.
“We have been hearing about the promise of nanomedicine for a long time, but it is now really starting to move,” said Dan Peer, who runs a nanomedicine laboratory at Tel Aviv University.
“There is a new level of confidence in this approach among the big pharmaceutical companies … We will see more and more products in clinical testing over the next few years and I think that is very exciting.”
Nanoparticles made of polymers, gold and even graphene – a newly-discovered form of carbon – are now in various stages of development. In cancer alone, 117 drugs are being assessed using nanoparticle formulations, though most have yet to be tried on patients, according to Thomson Reuters Pharma data.
Other potential applications include treatments for inflammatory disorders, heart and brain diseases, and pain.
COLLATERAL DAMAGE
Companies are increasingly focused on better drug targeting to increase efficacy and lessen the collateral damage caused by medicinal “carpet bombing” – a particular problem in cancer, where toxic compounds are needed to kill tumors.
The work on drug-carrying nanoparticles parallels advances in using so-called “armed antibodies” to deliver drugs direct to cancer cells – an approach championed by Roche.
The Swiss group won U.S. approval in February for Kadcyla, its first such antibody-drug conjugate, which treats breast cancer with fewer side effects like hair loss.
“All these developments have prompted companies to look at new avenues because the older ways of using drugs haven’t worked so well,” said Robert Langer, a pioneer of nanomedicine who runs the world’s largest biomedical engineering laboratory at the Massachusetts Institute of Technology.
Having worked on drug delivery since the 1970s, Langer has seen plenty of ups and downs.
The world’s first nanomedicine was actually approved back in 1995 when U.S. regulators gave a green light to Doxil for treating Kaposi’s sarcoma, a cancer often associated with AIDS.
Doxil – a hollow fatty ball known as a liposome with a cancer-killing drug inside it – was a breakthrough. Yet few other nanomedicines have followed.
Recent scientific advances have changed the game, however. Bind’s nanoparticles, for example, are programmed to reach the right spot using targeting molecules that recognize specific proteins linked to disease on the surface of cells.
They also have a stealth covering that shields them from the immune system, in order to minimize adverse reactions.
Since January, Amgen, Pfizer and AstraZeneca have all signed up to use Bind’s technology, which comes from work originally carried out in Langer’s lab.
And Bind is not the only game in town. Another approach, using tiny particles of gold as drug carriers, is being explored in a deal that AstraZeneca signed in December with CytImmune.
“Anything you can do to improve targeting of tumors rather than normal tissue – whether that is through an armed antibody or nanoparticle approach – increases the chance of success,” said Susan Galbraith, who leads AstraZeneca’s oncology research.
PARALLEL APPROACHES
The work remains early stage and Peer of Tel Aviv University says all the novel carriers will have to be studied closely for potential toxicity. However, experience with liposomes is good and versions of gold nanoparticles have also been used safely for many years to treat rheumatoid arthritis.
Injecting patients with gold may sound like a pricey option but with thousands of nanoparticles fitting into the width of a human hair, the amount of metal used is tiny. Gold, unlike some other metals, is not toxic and has been used in various medical treatments for many years without harmful effects.
Bind CEO Scott Minick also thinks his polymer technology will have cost advantages over expensive antibody drugs.
Further out, Kostas Kostarelos, professor of nanomedicine at University College London, has high hopes for graphene – a one-atom-thick form of carbon. His team is currently working with graphene nanomaterials in pre-clinical experiments.
“We will see parallel development of different materials, each offering something different therapeutically,” he said.
Other venture-backed nanomedicine firms include Cerulean Pharma, whose technology has made a highly potent cancer drug tolerable but which recently had disappointing results in a clinical study, and two companies looking at new vaccines.
Selecta Biosciences has a deal on food allergy vaccines with Sanofi, while Liquidia Technologies is allied with GlaxoSmithKline on vaccines and inhaled products.
MIT’s Langer is convinced more Big Pharma companies will think small in future.
“You can be sure others will jump on the bandwagon sooner or later. That doesn’t mean they might not jump off for a little bit too – but they will jump back on. These technologies are here to stay,” he said.
(Editing by Peter Graff)
Scientists have studied two dead stars that give us a glimpse, they say, of what our Solar System might look like a few billion years from now.
Our Sun will expand outwards when its nuclear fuel runs low and will ultimately blow off its outer layers.
Some of the inner planets will be consumed in the process and asteroids will be thrown out of their orbits.
A Cambridge-led team says it has seen evidence for this big upheaval in the atmospheres of the two burnt-out stars.
And the researchers believe their study has also given them some further insight on where planets can exist in our Milky Way Galaxy.
The pair of dead stars resides in the Hyades cluster, in the Constellation Taurus, about 150 light-years from Earth. They are so-called white dwarfs – the exhausted cores of average-size stars not unlike our Sun.
The astronomers used the Hubble Space Telescope to probe these two remnants, deciphering their chemistry with the observatory's powerful Cosmic Origins Spectrograph.
This showed the dwarfs to be "polluted" with silicon – the element found in the rocky material that makes up the Earth, the other inner planets in our Solar System, and its asteroids.
It is an indication that rock is falling on to the dead stars, their gravity likely shredding the material and spreading it out into a thin disc as it gets pulled ever closer.
"Stuff must be falling on to [each] star at a very high rate," explained Dr Jay Farihi of Cambridge's Institute of Astronomy.
"We can calculate the number of grams per second. That turns out to be something like a small river's worth of material.
"And based on the whole phenomenon of polluted white dwarfs and what we've learnt in the last few years, we know that there's a disc of material that must be feeding the star's atmosphere with this silicon-rich material," he told BBC News.
"That disc has to come from some disrupted, torn-apart planetesimal. The easiest way to describe it is a modest to large-sized asteroid."
Computer modelling suggests that as ageing stars throw off their outer layers and lose mass to become a dwarf, they destabilise the environment around them.
It becomes gravitationally perturbed, with any big planets still orbiting the dead star then nudging smaller rocks in all directions – many of them towards the dwarf.
Hubble's Hyades observations are very probably showing us this process in action. And it is a vision of what is to come for our own Sun.
In just a few billion years from now, it will use up all of its hydrogen fuel and will swell to become a red giant. Finally, it will dump a large proportion of its gaseous mass to leave a hot, compact and faintly glowing ember.
It also should be pulling in rocks that get too close, gravitationally pulverising them into a thin disc that gradually and continually dopes the remnant atmosphere with silicon.
Clusters like Hyades are places where many stars are born and live relatively close by to each other. But they are also locations where very few planets have thus far been detected.
To date, of the roughly 800 planets catalogued beyond our Solar System, only four are known to orbit stars in a cluster. That may be because these places are very energetic, which makes it difficult to discern orbiting planets using our current observation techniques.
What this latest research implies, however, is that stars in clusters almost certainly do have planets.
"The body responsible for [the silicon pollution] we see must have been an asteroid about 50-100km in size," Dr Farihi told the BBC's Material World programme on Radio 4.
"Asteroids or big rocks are really the building blocks of planets, so the fact that we're seeing giant rocks at these stars means that terrestrial planets were built during the stars' energy-producing lifetime.
"The question of whether they retain those planets to this day is a little bit more tricky. I would venture to say 'yes', because we need large planets to push these rocks around so that they can get close to the star and pollute its atmosphere."
Dr Farihi's team reports its work in the Monthly Notices of the Royal Astronomical Society.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
The UK's first national collection of tree seeds has been established, which scientists say is crucial as a growing array of pests threaten native species.
Co-ordinated by Kew's Millennium Seed Bank, it aims to safeguard the genetic diversity of the UK's tree flora.
The scheme will initially target 50 native species, including the common ash, which is under threat across Europe from ash dieback.
The project's funding has been provided by the People's Postcode Lottery.
"In the last 10 years, we have seen an increasing threat to our trees from many newly arrived, often very aggressive, pests and diseases," explained Paul Smith, head of Kew's Millennium Seed Bank.
"In 2013, almost all of our favourite tree species – from oak to beech and ash – are affected."
Safeguarding species
Researchers involved in the collection will focus their efforts on 50 species, which have been selected and ranked according to a range of criteria, including conservation status, prevalence in the landscape and vulnerability to pests and diseases.
"We currently don't have such a facility, and the UK is unusual in that, where you have access to a wide range of diversity in one place," Dr Smith told BBC News.
"We send out seeds all of the time all over the place, as well as in the UK, so it is ironic that we do not have comprehensive collections for the most important trees in our landscape."
In partnership with the Forestry Commission, the scheme will collect seeds of the prioritised species from 24 seed zones, identified by the commission, across the UK.
A species will only be considered to be fully represented in the national tree seed collection when it has been collected across its distribution or from all genetically distinct populations.
Dr Smith observed: "We have looked at our native species first because they are out there in the landscape and many of them are vulnerable.
"New pests and diseases have come into the UK, so there is an urgency related to that.
"In terms of genetic diversity, although we have the vast majority of tree species in the seed bank, we only have one or two collections from each [species] so you are not sampling right across populations.
"One thing that ash dieback has made clear is that only a subset of the UK population may have resistance, so you really need to be collecting right across the genetic spectrum in order to be able to provide a wide range of material for screening purposes."
Since being recorded in the UK's wider environment for the first time in 2012, ash dieback had propelled the issue of tree health into the headlines.
Researchers at the John Innes Centre (JIC) and The Sainsbury Laboratory (TSL) recently released the first cryo-electron microscope images of the fungus responsible for causing ash dieback.
"The benefit of this method is that the sample is imaged in as close to its natural state as possible, providing the best quality 3D view of an organism and its topography," explained JIC researcher Prof Allan Downie.
"We want to understand how the fungus makes the fruiting bodies (toadstools) that produce the spores.
"We think the spores cause infection of ash. We think the fungus growing within the ash leaf stem produces sex organs and that the images show such an organ."
Dr Robin Probert, head of conservation and technology at Kew's seed bank, explained why ash was listed as one of the collection's priority species.
"We need to collect multiple populations of ash throughout its range in the UK in the hope that we will find disease-resistant populations," he told BBC News.
"If we have that material and it is stored here, then it means that it is available for people to carry out that research to check for disease resistance and perhaps use that material as starting stock for strains that can be replanted back into the wild.
"It is the same story for all the other tree species that we are looking to collect and preserve. Until now, there has not been a push to build up a full genetic representation of important tree species, and ash happens to be one of them."
Temperature tolerance is key to the spread of wasp spiders into northern Europe, according to scientists.
Piecing together the genetic puzzle, he found that the spiders diverged after the last ice age: part of the population stayed on the Mediterranean while a colony headed east to Central Asia.
While these eastern populations adapted to live in climates as diverse as the tropical south of Japan and cold south-eastern Siberia, the spiders in the Mediterranean remained limited to warm areas.
But, according to the research, rising temperatures across the continent in the last century allowed the Mediterranean spiders to join up and breed with a previously isolated Black Sea population.
"This possibly restored genetic variation within a few generations and allowed for rapid adaptation," said Mr Krehenwinkel.
He theorised that the novel combination of genes resulted in new physical characteristics that helped spiders to survive in different environments.
To test the whether these more northerly spiders adapted a different temperature tolerance than Mediterranean populations, the PhD student analysed how they reacted when moved into one another's habitats.
Southern spiders could not survive the freezing temperatures in the north, and their counterparts suffered from heat stress in the south.
Mr Krehenwinkel explained that the eastern population had adapted to cooler temperatures and this was passed on to European spiders in the population boom.
The result was the rapid adaptation of hardier offspring that could settle further north than their predecessors.
The spiders found in northern Europe have smaller bodies and are not seen in the coldest months of the year.
Scientists attribute both traits to seasonal changes which do not affect southern species. Spiders found in northern Europe "overwinter", meaning their young are buried during the coldest months; emerging in spring.
The spiders then have limited warm months in which they can mature, which restricts how large they can grow before they reproduce in the autumn and the cycle begins again.
Mr Krehenwinkel described the hatchlings as "highly dispersive", commenting that they can cover huge distances via a method known as "ballooning": riding the breeze on a special parachute made of gossamer silk threads.
"By aerial dispersal, little spiders can cover distances of several hundred kilometres," he told BBC Nature.
"Members of different genetic lineages can thus quickly track warming climate, which increases the likelihood of contact."
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The worst offending countries in the ivory trade have been given a strict deadline to reduce their involvement or face sanctions.
The decision taken at the final meeting of the Cites conference in Bangkok is meant to compel countries like China and Thailand to tougher action.
But some campaigners say Cites is failing to protect elephants and want more urgent action.
Data indicates that 17,000 elephants were killed by poachers in 2011.
This is the most up-to-date information available for areas monitored by Cites.
In its final session here in Bangkok, delegates approved a decision to demand a clear set of targets for reducing the trade in ivory from the countries deemed the worst offenders.
The âgang of eightâ countries include the supply states, Kenya, Tanzania and Uganda, plus the consumer states of China and Thailand. The group also includes three countries – Malaysia, Vietnam and the Philippines – which are important in the transit of ivory.
The meeting heard that six of the eight countries had now come up with action plans.
The standing committee of Cites also agreed that if the actions described in those plans were not completed then sanctions against the offending country, or countries, could be taken from July 2014.
Secretary General of Cites, John Scanlon, explained that the deadline was real.
âThe eight states are prepared to do more and be measured against that," he said. "There is also a recognition that a failure to take action, [may see] the standing committee consider compliance measures. And the ultimate sanction under our convention is a trade suspension."
But the lumping together of the eight countries as worst offenders has upset several of the countries.
Speaking in the final session, Patrick Omondi, the spokesman for Kenyaâs delegation, drew a major distinction between the actions being taken by source and consumer countries.
âThe demand reductions strategies (in Thailand and China) are totally different from what we are supposed to be doing. Ours depend on resources.â
If you give me screens to screen tonnes of containers weâll screen all containers passing through Mombasa airport. If you give me 50 more sniffer dogs, weâll be sniffing every animal part that passes through,â he added.
Thailandâs legal domestic market has been highlighted at this meeting as being a particular source of concern. It is believed that criminal gangs take advantage of this loophole to launder ivory from African elephants into Asia.
At the start of the meeting, the Thai Prime Minister Yingluck Shinawatra accepted that her country needed to change its laws.
The conference also discussed other measures in the fight against elephant poaching.
The delegates decided to require countries that make seizures of ivory to send samples for DNA analysis to established facilities.
They also asked countries with stockpiles of ivory to give up-to-date information on the scale of these holdings. Many experts fear that ivory from these stockpiles is being diverted into the markets.
Jason Bell from the International Fund for Animal Welfare agreed that these steps would help.
âThese developments will not stop the current poaching crisis that is killing up to 25,000 elephants per year, but they will help and they should save some elephants,â he said.
But many campaigners were unimpressed by the Cites stance. A group of 10 conservation and welfare organisations issued a statement saying they were outraged by what they term as âthe failure of Cites to stop the poachingâ. They want a much tougher approach taken, especially with respect to China.
âChina could end the killing by immediately closing its domestic ivory markets and severely punishing citizens engaged in illegal ivory trade," said Steve Itela, director of Youth for Conservation.
âBut it chooses ivory trinkets for a luxury market over live elephants,â he added.
A group of environmental researchers says that legalising the trade in rhinoceros horn is necessary to save the animals.
"The current situation is failing, the longer we wait to put in place a legal trade the more rhinos we lose," he told BBC News.
"It is an urgent issue, we must start the process of getting a legal trade evaluated and put in place soon."
At present it is estimated that there are around 20,000 white rhinos left with the majority in South Africa and Namibia. There are also an estimated 5,000 black rhinos still alive, but the western black rhino was declared extinct in 2011.
Any trade in rhino horn is prohibited under the Convention on the international trade in endangered species (Cites). Delegates from 178 countries will meet in Bangkok next week to update the 40 year old treaty.
But according to the Science paper, the ban is actually boosting illegal poaching by constricting the supply of rhino horn and driving up the price. In 1993 a kilogramme sold for around $4,700 – In 2012 it was selling for $65,000 for the equivalent weight.
Attempts to restrict the trade by persuading consumers of Chinese medicine that rhino horn has no therapeutic effect have also failed.
In their report, the researchers argue that by humanely shaving the horns of live rhinos, enough material could be generated to meet global demand. Rhinos grow about 0.9kg of horn each year and the scientists say that the risks to the animals from horn "harvesting" are minimal.
The researchers advocate the setting up of a central selling organisation that could DNA fingerprint the shavings and control the market. Rhino horn would be legal, cheaper and easier to obtain they say.
But many wildlife campaigners fundamentally disagree.
"We don't support the idea of legalised trade at this time because we just don't think it is enforceable," says Dr Colman O'Criodain, a wildlife trade policy analyst with WWF.
"The markets where the trade would be directed, particularly Vietnam, we aren't satisfied that they have the enforcement regime in place that would prevent the laundering of wild rhino through this route."
"We don't think it would stop the poaching crisis, we think the legal trade could make it worse," he added.
But Dr Biggs and colleagues point to the experience with crocodiles as an example of how a legalised trading regime can work for the benefit of a threatened species.
"There has been a very successful legal trade for some time now which has more or less eradicated pressures on wild crocodile populations," he said.
"We have strong evidence that it works and the crocodile example shows it can work in low income countries and those without a strong governance structure."
The scientists say they don't like the idea of a legalised trade but believe it is the lesser of two evils. They also argue that because of the trade ban, conservation resources are being taken away from other actions and are being redirected to anti poaching.
"Essentially what is being created is a pseudo war with people some from the local communities who are involved in poaching," says Dr Biggs.
While no proposal to lift the ban is on the table at next week's Cites meeting in Bangkok, the South African government is said to be investigating the issue and says that discussions in the Thai capital will guide their position.
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A livestock virus sweeping through British sheep flocks and cattle herds has infected wild deer, say scientists.
Dr Garigliany said wild animals such as roe and red deer can potentially act as a reservoir of infection.
"It is just impossible to control midges across an area the size of Europe," Prof Drew told the Environment, Food and Rural Affairs select committee.
"Even if we had some national campaign, it would be quite simple that the midges would be blown over and of course we cannot control the disease in wild deer."
The UK's deputy chief veterinary officer, Alick Simmons, said a vaccine against SBV is not yet available but several are being developed.
"This is a disease which we believe will either through vaccination or through natural spread become less of a problem over time," he told the committee.
"And already in the areas we have been affected in northern Europe and to a certain extent in the south east of England, the disease is less than it was last year."
SBV, named after the German town where it was first detected, is an emerging livestock disease in Europe.
It was found in south east England early in 2012, and has since spread to every county in England and Wales.
SBV is not a notifiable condition, suggesting official figures on the number of outbreaks are a vast underestimate.
Scientists are set to release the first batch of data from a project designed to create the first map of the human brain.
The brain's wiring diagram is not like that of an electronic device which is fixed. It is thought that changes occur after each experience, and so each person's brain map is different – an ever changing record of who we are and what we have done.
The HCP will be able to test the hypothesis that minds differ as connectomes differ, according to Dr Tim Behrens of Oxford University, UK.
"We're likely to learn a lot about human behaviour," he told BBC News.
"Some of the connections between different parts of the brain might be different for people with different characters and abilities, so for example there's one connection we already know about in people who like taking risks and (a different one) for people who like playing it safe.
"So we'll be able to tell the type of people who like skydiving and who would rather watch TV from their brain scans.
"It will be an amazing resource for the neuroscience community to help them in their work to understand how the brain works," he said.
Prof Steve Petersen, who works with the HCP at Washington University in St Louis, wants to identify the different parts of the brain involved with our ability to think about scientific problems, to concentrate and to hold information in our memory.
"The romance to me is that we are getting to our humanity," he said.
The world's cargo ships are getting big, really big. No surprise, perhaps, given the volume of goods produced in Asia and consumed in Europe and the US. But are these giant symbols of the world's trade imbalance growing beyond all reason?
Overcapacity in the world's ports means there is huge competition for business. Operators cannot afford to get left behind, says Marc Levinson, author of The Box – How the Shipping Container Made the World Smaller and the World Economy Bigger.
"These days with the increase in traffic, we experience this more and more often," says Marco Pluijm, a port engineer working for Bechtel. "A simple thing you can do is just slow ships down and add some tug boats for better manoeuvring – but that all has cost implications."
Although it will only be three metres longer and three metres wider than the 15,500-TEU Emma Maersk, its squarer profile allows it to carry 16% more cargo.
Maersk's Triple Es will be going into service at a time when growth in the volume of goods to be shipped is comparatively low – some experts don't expect it to pick up until 2015. But the world's container fleet capacity is expected to grow by 9.5% this year alone, as Maersk and others receive the ships they ordered years ago.
Some of the extra capacity will be absorbed in the new practice of slow steaming – industry-speak for sailing more slowly. Sailing at 12-15 knots instead of 20-24 knots brings enormous savings on fuel – but it does mean that extra ships are required to transport the same volume of goods in the same timescale.
Maersk are counting on container trade continuing to grow at 5-6% – less than half the growth rate of seven years ago, but enough to recoup the company's investment in the Triple Es, which cost $190m (£123m) each.
"The history of container shipping involves ship lines taking huge gambles," says Marc Levinson, who points to a trend for some American and European companies to move manufacturing back from Asia.
"There are a lot of people in the shipping industry who aren't sure that Maersk is on the right track," he says.
Jean-Paul Rodrigue at Hofstra University believes that big container ships like the Triple E will prove their value on specific trade routes, nonetheless.
"Each time a new generation comes along, there's the argument 'Oh is this going a little too far this time – is there enough port trade to justify this?'" he says.
"But each time the ship class was able to put itself in the system and provide a pretty good service."
Marco Pluijm was interviewed on the BBC World Service programme The Forum.
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