Day: 08/30/2013

Dean Karnazes: the man who can run for ever.

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Most runners have to stop when they reach their lactate threshold, but Dean Karnazes‘ muscles never tire: he can run for three days and nights without stopping. What’s his secret?

From club runners to Olympians, every athlete has a limit. Scientifically, this limit is defined as the body’s lactate threshold and when you exercise beyond it, running rapidly becomes unpleasant. We’ve all experienced that burning feeling – heart pounding, lungs gasping for air – as your muscles begin to fatigue, eventually locking up altogether as your body shuts down. However, there is one man whose physiological performance defies all convention:Dean Karnazes is an ultrarunner from California and, at times, it seems as if he can run forever.

Karnazes has completed some of the toughest endurance events on the planet, from a marathon to the South Pole in temperatures of -25C to the legendary Marathon des Sables, but in his entire life he has never experienced any form of muscle burn or cramp, even during runs exceeding 100 miles. It means his only limits are in the mind.

“At a certain level of intensity, I do feel like I can go a long way without tiring,” he says. “No matter how hard I push, my muscles never seize up. That’s kind of a nice thing if I plan to run a long way.”

When running, you break down glucose for energy, producing lactate as a byproduct and an additional source of fuel that can also be converted back into energy. However, when you exceed your lactate threshold, your body is no longer able to convert the lactate as rapidly as it is being produced, leading to a buildup of acidity in the muscles. It is your body’s way of telling you when to stop – but Karnazes never receives such signals.

Dean Karnazes running

“To be honest, what eventually happens is that I get sleepy. I’ve run through three nights without sleep and the third night of sleepless running was a bit psychotic. I actually experienced bouts of ‘sleep running’, where I was falling asleep while in motion, and I just willed myself to keep going.”

While supreme willpower is a common trait among ultrarunners, Karnazes first realised that he was actually biologically different when preparing to run 50 marathons in 50 days across the US back in 2006. “I was sent to a testing center in Colorado,” he recalls. “First, they performed an aerobic capacity test in which they found my results consistent with those of other highly trained athletes, but nothing extraordinary. Next, they performed a lactate threshold test. They said the test would take 15 minutes, tops. Finally, after an hour, they stopped the test. They said they’d never seen anything like this before.”

As Laurent Messonnier from the University of Savoie explains, the difference is that your aerobic capacity is a measure of your cardiovascular system performance, while your lactate threshold is your ability to clear lactate from your blood and convert it back into energy.

“If you take a high-level runner and you train that guy for a long time, his cardiovascular system will improve until a certain point where it will be very difficult to improve it further, as it’s determined by the heart and the blood vessels. So if you carry on training that guy, you will not improve his aerobic capacity but his performance will still improve, because the lactate threshold is not limited by the cardiovascular system – it’s determined by the quality of the muscles.”

Your body clears lactate from the blood via a series of chemical reactions driven by the mitochondria in your muscle cells. These reactions transform lactate back to glucose again and they are enhanced by specific enzymes. The clearance process also works more efficiently if your mitochondria have a larger capacity, increasing their ability to use lactate as a fuel.

Years of training will improve both your enzymes and mitochondria and so improve your clearance, but there is a limit to how much you can improve your lactate threshold by training alone. If you inherit these enzymes and a larger mass of mitochondria genetically, your personal limits will be far higher.

Karnazes fell in love with running from an early age, and at high school he began to show endurance capabilities which far surpassed those of his peers. At one charity fundraiser, while his fellow runners were able to manage 15 laps of the track at most, Karnazes completed 105. But in his mid-teens he stopped altogether until experiencing an epiphany on his 30th birthday. Gripped by a powerful desire to run once more, he set off into the night.

After 15 years of no training, most of us would not have been physically capable of getting too far, but Karnazes did not stop until 30 miles later. Although the blisters were excruciating, his muscles showed little sign of fatigue.

“Many elite distance runners will show some improvements in their ability to clear lactic acid from the system due to the ‘training effect’, but that only goes so far,” he says. “The rest, as I am told, is left up to heredity. They say the best thing you can do as a long-distance runner is to choose your parents well!”

However, genetics alone does not tell the full story. Karnazes believes that his lactate clearance abilities could also be down to low body fat, low sweat rate, a highly alkaline diet and low exposure to environmental toxins. Genetics can give you the propensity for a natural advantage but you express your genes differently depending on your environment and your lifestyle.

The intriguing question is whether Karnazes’ lactate clearance abilities would be the same now if he had not done so much running at an early age.

“If you take two twins – one grows up in Africa and one grows up in northern Europe – their athletic performance will potentially be very different, because they will express their genes differently as the environment, food, everything is different,” Messonnier says.

An interesting experiment could be to repeat the lactate threshold test with Karnazes’ brother.

“He plays competitive volleyball but has never really done an extensive amount of running,” Karnazes says. “I would be curious if he exhibits some of those same abilities to clear lactic acid from his system.”

Source: http://www.theguardian.com

Kenyan doctor uses cancer drug to stop HIV progress. Is this it?

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Five Kenyans, two men and three women appear to have overcome the HIV virus. This was said by the man leading the clinical trials of the unconventional regimen, Dr. Barasa Situma, a practicing pharmacist and lecturer at the Technical University in Nairobi who has been researching the HIV virus for years now.

These five among many others were treated with methotrexate, a drug that works by suppressing rapid expansion of the specialized stem cells in the bone marrow- hematopoietic cells, frequent lab tests have shown that the viral loads are now undetected. There was improvement after six months and after a year, test showed that they are free of the HIV virus.

The drug works by stopping rapid multiplication of CD4 progenitor cells in the bone marrow, where the HIV virus hides to avoid elimination by the immune system. Hence it get rid of the reservoir of the virus which the ARV’s are not able to reach.

Methotrexate has very serious side effects, hence should not be used without the advice of a physician.

Is this the cure for the world’s deadliest virus? This raises the hopes of a cure for the disease still deemed uncurable but manageable.

All the patients were confirmed to be HIV positive and after treatment the viral loads were undetectable even by the most advanced laboratory in Kenya, The Kenya Medical Research Institute ( KEMRI).

KEMRI said in a statement that they are not sure how this happened, but it is true that the patient are cured of HIV. It took them more than a week to monitor the tests and confirm that they are HIV negative.

The patients continue with the ARV’s while on methotrexate treatment.                                        

Is this it? Or this cocktail of drugs playing a wily game with Kenya’s laboratories?

For the cocktail to be effective, the patient must be started on it early enough.

 

 

Polio Crusade: The Success Staircase.

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Following two long hauling decades of global vaccination campaign, the world is at the edge of eradicating polio. Pakistan is one of the only three countries, labouring under a huge burden of polio, Afghanistan and Nigeria being the other two. The national campaign to wipe out polio and various deadly diseases from the roots have feared failure for the past few years and very recently, a devastating blow when the murders of the aid workers made headlines and pushed the agencies to suspend the Polio Crusade. Over 90 percent of the polio cases being reported are from four major transmission zones in Fata, Khyber-Pakhtunkhwa (K-P), Baluchistan, central Punjab and Sindh.

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Pakistan declared a national health emergency in January 2011 uncovering an action plan with a singular goal of disrupting transmission of the disease by the year’s end. Unfortunately, the initiative failed. A recent intensification of the disease with emerging violence has been highlighted, which unfortunately continues up to date. The incidence of the highly infectious disease is relatively low in the peaceful areas, Punjab and Sindh and high in KPK, FATA and Baluchistan.

In 2011, Pakistan reported 198 fresh cases, being the highest in the world. Over 188 out of the 198 new infections reported to have emerged from the violence-plagued areas. Similarly, 55 out of 58 cases in 2012 emerged from Baluchistan, FATA and KPK. The ruling under the new leadership could have the government to eradicate polio from Pakistan; a goal we have almost achieved. However, in the light of recent attacks on the health care personnel, which included women, have raised fear and subsequent departure from respective duties, abandoning the vaccination campaigns and various health associated activities.

Many have spoken about the government responsibilities, highlighted the need for education of the masses, remote accessibility, promising security services and making this world an infection-free place to live in. However, Polio and I sat down with the Pakistani dilemma where we discussed weaknesses thereafter coming up with a plan we called the Success Staircase. Polio highlighted the first step towards eradication – Health education, which by definition is a positive impact on individual, which results in a favourable behavioural change, leading to good health. Health education in primary health care aims to foster activities that encourage people to want to be healthy, know how to stay healthy, do what they can to maintain health and seek help when needed.

It remains the duty of all conscientious persons dealing with each other in everyday life. Therefore, it starts form “Us”. – The second step towards enlightenment as mentioned by polio was sensitization. This step is overlooked by the authorities who race towards achieving bigger goals neglecting the basics.

Therefore, the nation can come up with new ideas, polices and agendas once we have successfully eradicated polio. Those who have access to health care services should be given a tutorial supplemented with visuals (as seeing is believing) whereas those who remain unattended and unreachable should be approached through media and community leaders. In health campaigns driven in the country so far, no special efforts have been dedicated to reach to the illiterate population. Do we and our future really require clothing labels, processed food, tea and telecommunication plans to recover our health liabilities?

How about we incorporate polio awareness regimens with the existing advertisements. We can target the product consumed/adopted widely by the masses to spread knowledge. For example, through the mobile facility, we can extend text/pictorial messages and offer free tele-health services. Polio and Publicity go hand in hand.

Back in my childhood days, I memorized a jingle that played in a short advertisement of a family planning service. I sang it like all other poems from the recitation classes. A very good example in today’s time emanates from the practice of hand-washing which is a primary step towards nipping the disease in the bud. The hand-wash product came up with a good theme and a child friendly song, bagging nationwide incentive.

My idea was to contemplate campaigns and advertisements in an entertaining approach to grab mass appeal. Instead of having crippled children look at the sight of ordinary kids performing daily activities coupled with a distressing melody in the backdrop, make the practice of inoculation fun and enamouring. Bright colours, energetic theme and lively environment is definitely heartening. Even the census participation was made encouraging due to the cheerful rattle; it ran over the tube a hundred times in a day resultantly.

Polio asked to re-establish priorities. In addition to door-to-door services, establish and push school-to-school and community–to-community agenda forward. Bangladesh is becoming an emerging economy showing cohesive tendencies to various changes and demands. It achieved a huge reduction in poverty; there has been a growth in trade and education, overcoming most of their challenges.

Therefore, in order for Pakistan to grow into a healthy nation, we need a collective collaboration and sustenance program and adequate funds free of manoeuvre. Continued education and training of the health care personnel is a very important step towards the quality of implementation. The trainees should be motivated and expectant for absolute health care delivery. A very important aspect of this exercise remains bridging the communication gap.

Special attention should be given to areas of barriers such as social and cultural divide, negative attitudes, insufficient emphasis and contradictory messages. The trainees should also be offered attractive quality packages keeping in mind the objectives of occupational health; thereby encouraging performance and dedication. Special training and advancements should be offered to promote remote access and healthcare relief. Considering the recent event in the lawless areas, operations and killings of the charity and aid workers had gripped the localities with fear.

Polio emphasized upon security as a requisite for the protection of the conduct. All health associated movements and activities should have satisfactory safety arrangements due to various events in history that have endangered medicine and medical practice. Polio and I spent hours discussing the merits of pressing a campaign in a low profile manner where authorities could inoculate children in phases, with adequate security arrangements instead of pulling off a nationwide campaign which may not only be strenuous to supervise but also under-productive. Another idea that hit us was to offer general healthcare facilities which obviously encased the polio proposal instead of highlighting special polio camps and workers.

This attempt could smash its way into successful inoculation of a child at a routine visit and subsequent education of the guardian. Polio called in for an enterprise which could regain trust. The government should re-think the measures previously taken for the medical movement; making nationwide announcements for a child friendly campaign. Local authorities should scheme initiatives entitled to gain confidence of the masses which is the gateway to reliance upon the government.

Pharmaceutical fraud is the biggest threat to the integrity of the global drug supply. With meager training and knowledge, the criminals have made their way in the market generating illegitimate profits. The impact of the convincing fakes has a potential to contribute to world health crisis. The government should run and revise inspection and subsequent quality control programs and announce strict penalties to the offenders.

Our great emphasis has been on the government abilities. Our system should realize the crisis Pakistan is falling into. We as health officials should join forces to formulate a singular agenda instead of feeding our personal motives, with a sole purpose of a Healthy Nation, Healthier Environment, and the Healthiest People.

References:

http://www.emro.who.int/countries/pak/ http://europe.wsj.com/home-page http://tribune.com.pk/




Rising ocean acidity will exacerbate global warming.

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Carbon dioxide soaked up by seawater will cause plankton to release less cloud-forming compounds back into atmosphere.

The slow and inexorable increase in the oceans’ acidity as they soak up carbon dioxide from the atmosphere could itself have an effect on climate and amplify global warming, according to a new study. Acidification would lead certain marine organisms to emit less of the sulphur compounds that help to seed the formation of clouds and so keep the planet cool.

Atmospheric sulphur, most of which comes from the sea, is a check against global warming. Phytoplankton — photosynthetic microbes that drift in sunlit water — produces a compound called dimethylsulphide (DMS). Some of this enters the atmosphere and reacts to make sulphuric acid, which clumps into aerosols, or microscopic airborne particles. Aerosols seed the formation of clouds, which help cool the Earth by reflecting sunlight.

James Lovelock and colleagues proposed in the 1980s that DMS could provide a feedback mechanism limiting global warming1, as part of Lovelock’s ‘Gaia hypothesis’ of a self-regulating Earth. If warming increased plankton productivity, oceanic DMS emissions might rise and help cool the Earth.  

More recently, thinking has shifted towards predicting a feedback in the opposite direction, because of acidification. As more CO2 enters the atmosphere, some dissolves in seawater, forming carbonic acid. This is decreasing the pH of the oceans, which is already down by 0.1 pH units on pre-industrial times, and could be down by another 0.5 in some places by 2100. And studies using ‘mesocosms’ — enclosed volumes of seawater — show that seawater with a lower pH produces less DMS2. On a global scale, a fall in DMS emissions due to acidification could have a major effect on climate, creating a positive-feedback loop and enhancing warming.

The sulphur factor

Katharina Six at the Max Planck Institute for Meteorology in Hamburg, Germany, and her colleagues have applied these mesocosm data to a global climate model developed at their institute. In a ‘moderate’ scenario described by the Intergovernmental Panel on Climate Change, which assumes no reductions in emissions of heat-trapping gases, global average temperatures will increase by 2.1 to 4.4 °C by the year 2100.

The model projected that the effects of acidification on DMS could cause enough additional warming for a 0.23 to 0.48 °C increase if atmospheric CO2 concentrations double. The moderate scenario projects CO2 doubling long before 2100. Their paper is published in Nature Climate Changetoday3.

“The result in itself doesn’t surprise me too much,” says Michael Steinke, a researcher at the University of Essex. But he thinks that incorporating such results into predictive global models is important. “This is something that hasn’t really been done very much yet,” he says

However, Steinke points out a recent study of his own4 indicating that oceanic DMS emissions might be more affected by increasing temperature than acidity. Warmer waters tend to make more DMS, so it could increase overall in future. The new study does take warming into account, but Steinke emphasizes that the effect of acidification on DMS production is better understood than that of other human-induced environmental changes.

Tom Bell, a marine biogeochemist at the Plymouth Marine Laboratory in the UK, advises caution in extrapolating mesocosm data obtained over weeks into changes occurring over decades. Six recognizes that limitation in her team’s study. “It is definitely not encased in stone.” She points out that there have been no mesocosm experiments in tropical and subtropical regions, and that running simulations with different models would help to rule out error.

All agree that it is important to recognize that marine organisms will be affected by environmental changes and that this may impact the climate in return. “CO2 that is absorbed by the ocean is still climate-relevant”, says Six.

Soure:Nature

Desert plantations could help capture carbon.

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Planting trees in coastal deserts could capture carbon dioxide, reduce harsh desert temperatures, boost rainfall, revitalise soils and produce cheapbiofuels, say scientists.

Large-scale plantations of the hardy jatropha tree, Jatropha curcas, could help sequester carbon dioxide through a process known as ‘carbon farming’, according to a study based on data gathered in Mexico and Oman that was published in Earth System Dynamics last month (31 July).

Each hectare of the tree could soak up 17-25 tonnes of carbon dioxide a year, they say, at a cost of 42-63 euros (about US$56-84) per tonne of gas, the paper says. This makes the technique competitive with high-tech carbon capture and storage.

Klaus Becker, the study’s lead author and director of carbon sequestration consultancy Atmosphere Protect, says that a jatropha plantation covering just three per cent of the Arabian Desert could absorb all the carbon dioxide produced by cars in Germany over two decades.

“Our models show that, because of plantations, average desert temperatures go down by 1.1 degree Celsius, which is a lot,” Becker says. He adds that the plantations would also induce rainfall in desert areas.

Jatropha, which is a biofuel crop, needs little water, and coastal plantations would be irrigated through desalination, Becker says.

He also envisages a role for sewage in such large-scale plantations.

“There are billions and billions of litres of sewage that are discharged into the oceans every week, but instead we could send that water to the desert and plant trees,” he says. “In this situation, you wouldn’t need any expensive artificial nitrogen [to fertilise the trees].”

The team has also been working in Israel’s Negev desert, where they planted 16 tree species, which, they say, is preferable to a jatropha monoculture. “A diversity of trees is good for the environment, good for investors and good for preventing diseases,” says Becker.

At another of the team’s carbon farms — a jatropha plantation in Madagascar — the organic matter content of degraded soil has risen from 0.2 per cent up to three per cent.

Local people now harvest beans planted between the trees, providing a vital source of protein and creating a symbiotic exchange of nitrogen — fixed from air by beans — and shade provided by the jatropha trees.

“Previously, no one had the idea of using uncultivated land to plant these kinds of leguminous beans because they would not grow there. But after four or five years of applying cultivation techniques, the soil quality increases dramatically,” Becker says.

Alex Walker, a research assistant at the Centre for Environmental Policy at Imperial College London, United Kingdom, describes carbon farming as a “common-sense approach to rising carbon dioxide levels, with potentially positive biodiversity impacts”.

He adds: “It will grow on non-arable land, and so not compete with food production, but it is more difficult to process and subject to varying yields and absorption volumes”.

Egypt is pioneering an experiment in desert farming, using sewage water after basic treatment to produce wood, woody biomass and biofuel crops, such as casuarina, African mahogany, jojoba and neem, in addition to jatropha.
“In Egypt, there are 15,000 acres planted with trees of good quality but so far they have not been sold to create economic value,” Hany El Kateb, a professor at the Technical University of Munich in Germany, tells SciDev.Net.

According to El Kateb, Egypt produces more than 6.3 billion cubic metres of sewage water a year, and 5.5 billion cubic metres of this would be sufficient to afforest more than 650,000 hectares of desert lands and store more than 25 million tonnes of carbon dioxide annually in new forests.

El Kateb points out that Egypt has an advantage over European countries that are leaders in forestry, such as Germany, because the same trees grow more than 4.5 times faster in  Egypt where the sun shine most of the year.

But Mosaad Kotb Hassanein, director of the Central Laboratory for Agricultural Climate in Egypt, says: “One of the big challenges of planting forests in arid areas is the lack of experience, expertise and technical personnel involved in the establishment and management of forest plantations.

“The project in Egypt was lucky to have technical assistance and support establishing  a forest administration from the German Academic Exchange .

Source: http://www.scidev.net

Smartphones could provide weather data in poor nations.

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Smartphones can now be used to collect weatherdata such as air temperatures through WeatherSignal, a crowdsourcing app developed by UK start-up OpenSignal.

This helps crowdsource real-time weather forecasts and could one day help collect climate data in areas without weather stations, its developers say.

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Once installed, the app automatically collects data and periodically uploads them to a server.

The app’s ability to record air temperature is based upon the discovery that the temperature of a smartphone battery correlates closely to the surrounding air temperature, published in Geophysical Research Letters this month (13 August).

“Lithium ion batteries have temperature sensors to prevent damage caused by attempts to charge them when the battery is too hot,” the paper says.

But these sensors do not provide a direct air temperature measurement — due to heat being emitted by both the smartphone and its user. So the researchers used a model that estimates the outside temperature based on smartphone readings.

The fact that battery temperature correlates with ambient air temperature was discovered by accident, James Robinson, one of the authors of the paper and co-founder of OpenSignal, tells SciDev.Net.

“When data from many phones are joined together, they become even more powerful and will allow us to make weather predictions of unprecedented detail.”

James Robinson

The team was researching energy consumption in relation to poor mobile network signal, a condition that is known to reduce battery performance.

“We started playing with the data and decided to look at average battery temperature versus historic weather temperature, and we found a really strong correlation,” says Robinson.

The data came from eight major cities around the world covering a wide range of climate zones, and including Buenos Aires, Mexico City and São Paulo.

“Many smartphones have a variety of sensors,” says Robinson. “When data from many phones are joined together, they become even more powerful and will allow us to make weather predictions of unprecedented detail.

Developing countries often invest fewer resources in collecting weather data.

“As smartphones become more popular in developing countries, WeatherSignal could provide a valuable source of weather data — either supplementing existing sources or as the only source for some places,” he says.

“We’re open to working with as many people as possible,” Robinson says. “For instance, we plan on making historic data available to academics and organisations such as the World Meteorological Organization.”

Enzo Campetella, an Argentina-based meteorologist and WeatherSignal user, tells SciDev.Net that although the app has potential, “there are still several stages to accomplish” before it is completely reliable for use in meteorology.

“In meteorology, it is essential that data are comparable, so it is essential that they are collected following the same rules or standards,” he says.

And, in countries where weather stations are scarce, “the possibility of comparing data is much lower”, he explains.

The WeatherSignal team admit that “many additional high-quality urban observations [are] needed to refine the air temperature estimates from smartphones and to expand their possibilities”.

Having more data is also crucial, so they are also working to get as many people as possible using the app.

Source: http://www.scidev.net

GM bacteria could help mass produce hookworm drugs.

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Researchers have produced a protein that kills parasitic intestinal worms, by genetically engineering a bacterium similar to those used in probiotics — raising hopes of more effective and safer therapies for infections that affect up to two billion people worldwide.

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“There is a growing number of drug resistant parasites.”

Rose Gomes Monnerat 

The protein, Cry5B, has previously been shown to kill parasitic worms. It is normally produced by Bacillus thuringiensis, a bacterium used as an insecticide and not considered safe for use in people.

Bacteria containing Cry5B could be an ideal drug against human parasites, researchers say, as they can be easily and cheaply produced in large quantities, as well as shipped and stored under adverse conditions.

The researchers inserted the protein-producing gene into another related bacterium, Bacillus subtilis — strains of which are commonly used in foods such as probiotic yoghurts.

They first showed that the modified strain successfully produces the protein, and then tested it for treating parasitic worms in hamsters.

When given in small doses to hamsters infected with hookworm,Ancylostoma ceylanicum — which is capable of infecting people, and is related to a major human parasite, A. duodenale — the protein reduced the parasite burden by 93 per cent.

The study reports that this is comparable or even more effective than currently approved drugs for treating hookworms, whipworms and large roundworms.

These parasitic worms “are the leading causes of disease burden and disability in children and pregnant women worldwide” and “infect mostly impoverished people in the developing world and contribute significantly to keeping these people trapped in poverty”, the study says.

Rose Gomes Monnerat, a researcher at the Brazilian Agricultural Research Corporation (Embrapa), and a member of the study team, tells SciDev.Net: “Treatment of gut parasites has been done with highly toxic drugs so far.”

“There is also a growing number of reports of drug resistant parasites. So it is important to have alternatives to their control,” she adds.

Manoel Victor Franco Lemos, a biologist at São Paulo State University, Brazil, says: “Although the results have been achieved by using animal models of parasitic infections, the worm species used are quite close to those that cause the same infections in humans”.

But he highlights the need for trials on humans.

Raffi Aroian, co-author and a biologist at the University of California, San Diego, says: “We are talking to knowledgeable people about how much pre-clinical testing would have to be done prior to human clinical trials”.

One of the main challenges, Aroian adds, is that although the B. subtilisstrain used is a model for food-safe bacteria and used in some probiotics, it is not a proven food-safe bacterium.

“Now we need to put the gene into a proven food-safe one,” he says.

“Additionally, several toxicity tests must also be done until we can ensure its safety,” says Monnerat.

Source: http://www.scidev.net

50,000 kids to get self-adjusting eyeglasses.

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Nearly 100 million near-sighted teenagers in developing countries may soon be able to see normally without the need for specialist eye care as a project starts distributing specially designed glasses costing just US$15.

The Child ViSion project, which will begin handing out the first 50,000 pairs of their self-adjusting glasses in Asia this year, aims to provide affordable vision correction to all children who need it in the developing world.

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The initiative, paid for by donors and sponsors, is run by the UK non-profit Centre for Vision in the Developing World. They hope that establishing long-term distribution schemes via schools will bring down the costs.

“There are roughly 100 million myopic children in the developing world who need eyeglasses to see the board in class. The Child Vision glasses are essentially an educational intervention to get them to see clearly,” says the project’s founder and director, Joshua Silver.

The prototype glasses are a smaller, lighter and more fashionable version of the adult model, Adspecs. Both work by the wearer pumping silicone oil into the lenses, which change shape, allowing the user to instantly adjust the glasses to their needs.

Self-adjusting lenses are not new. Companies such as Focus on Vision have developed glasses with specially designed lenses that are adjusted by sliding them back and forth.

But according to Silver, Child ViSion glasses are the only variable-power design based on clinically tested data.

In the tests Silver and colleagues measured how accurately around 1,500 near-sighted teenagers aged 12 to 17 in China and the United States used the self-adjusting lenses. They found 95 per cent of children achieved vision just short of normal when looking at the standard eye chart.

“That’s good enough to function in class,” says Silver.

But, Peter Ackland, chief executive officer of the International Agency for the Prevention of Blindness, which leads the VISION 2020 programme along with the WHO, says the glasses are not a replacement for professional eye care.

“Our approach is to try to develop local services where you can get an eye examination at the same time as specs. If you bypass that, you’re going to miss fundamental eye problems that can cause serious problems later in life.”

In places such as Sub-Saharan Africa, however, there can be as few as one optometrist for every million people. Until that number increases, Silver says the glasses can be a useful temporary solution.

Source: www.scidev.net

Engineered spider toxin could be the future of anti-venom vaccines.

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New engineered spider protein could be the start of a new generation of anti-venom vaccines, potentially saving thousands of lives worldwide. The new protein, created from parts of a toxin from the reaper spider, is described today in the journal Vaccine.

The researchers behind the study, from the Universidade Federal de Minas Gerais in Brazil, say that the engineered protein may be a promising candidate for developing therapeutic serums or vaccines against other venoms.

Reaper spiders, or brown spiders, are a family of species found all over the world that produce harmful venoms. The toxic bite of these spiders causes skin around the bite to die, and can lead to more serious effects likekidney failure and haemorrhaging. TheseLoxosceles spiders are most prevalent in Brazil, where they cause almost 7,000 human accidents every year.

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The new study describes an engineered protein made of three pieces of a venom toxinfrom the Loxosceles intermedia spider. The engineered protein is not itself toxic, and gives effective protection against the effects of the pure spider venom in animal models.

“In Brazil we see thousands of cases of people being bitten by Loxosceles spiders, and the bites can have very serious side-effects,” said Dr. Chávez-Olortegui, corresponding author of the study. “Existing anti-venoms are made of the pure toxins and can be harmful to people who take them. We wanted to develop a new way of protecting people from the effects of these spider bites, without having to suffer from side-effects.”

Current approaches to protecting against venom involve giving the venom to animals, and taking the resulting antibodies for the serum. These antibodies enable the human immune system to prepare to neutralize venom from bites. Although they are somewhat effective, the production of anti-venoms like these is problematic because animals are required to produce them, and these animals suffer from the effects of the venom.

The new protein is engineered in the lab, without the need for the venomous animals. It is made up of three proteins, so it can protect against more than one kind of toxin at a time. The protein is not harmful to the immunized animal that produces the antibodies. It is also more effective than existing approaches, and easier to produce than preparing crude venom from spiders.

“It’s not easy taking venom from a spider, a snake or any other kind of venomous animal,” said Chávez-Olortegui. “With our new method, we would be able to engineer the proteins in the lab without having to isolate whole toxins from venom. This makes the whole process much safer.”

The researchers tested their new protein on rabbits: all immunized animals showed an immune response similar to the way they respond to the whole toxin. The engineered protein was effective for venom of the L. intermedia and L. gaucho sub-species, which have similar toxins. Immunized rabbits were protected from skin damage at the site of venom injection, and from haemorrhaging.

This engineered protein may be a promising candidate for therapeutic serum development or vaccination in the future.

 

Source: http://medicalxpress.com

Smart lenses make spectacles accessible to millions.

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Spectacles with variable lenses that can be adjusted by a wearer with no access to specialist eye care are being mass produced.

The first 30,000 pairs will be shipped to Afghanistan, Ghana and Tanzania by the end of the month.

Focusspec is the first self-adjustable lens to be produced in large quantities, though other similar glasses have been designed. The technology is expected to improve the lives of millions of adults in the developing world living with poor eyesight.

The spectacles were developed by Dutch industrial designer Frederik Van Asbeck, based on a discovery in 1964 by Nobel Prize-winning physicist Luis Alvarez. Alvarez designed a lens that was convex on one side and concave on the other. He found that by placing two such lenses on top of each other, and moving one relative to the other, the focus could be changed.

“The technology to produce those lenses with the needed high precision — an aberration of a micrometre will cause a headache — was developed only a few years ago,” Van Asbeck told SciDev.Net.

Anyone can adjust the strength of the lenses themselves, by turning wheels located on the side of the spectacles, eliminating the need for an eye expert.

Van Asbeck says Focus on Vision, serving the WHO’s VISION 2020 programme, will produce one million pairs of glasses a year in the Netherlands.

The glasses have been tested in Afghanistan, Cambodia, Ghana, India, Nepal and Tanzania.

“I see people’s faces light up when they adjust their spectacles and discover they can read again, take care of themselves, work, get an education,” says Jan in ‘t Veld, a board member for Focus on Vision, which undertook a large part of the fieldwork.

In ‘t Veld says the lenses are scratch-, UV-, water- and dust-resistant — and optically almost as good as the far pricier lenses used in Western countries.

Ben van Noort, co-board member and ophthalmologist, points out that Focusspec lenses can only be adjusted between +0.5 to +4.5 dioptre or -1 to -5 dioptre (most people wear between -6 and +6) and they are unsuitable for astigmatism. “Still, they work for 80–90 per cent of adults,” he says.

Lillian Mujemula, optometrist and main distributor of the glasses in Tanzania agrees: “Most of our clients live in remote areas, where there are no optometrists. People are very happy with the glasses because they are of good quality and easy to use. I believe people can wear them for many years.”

Brien Holden, professor of optometry in Sydney and chairman of the International Centre for Eyecare Education (ICEE) told SciDev.Net: “The FocusSpec has an important place as a stop-gap solution. But they cannot replace the long-term strategy of educating eye care personnel and creating optical workshops and distribution channels in each community in need”.

Holden also points out there is a need for proper scientific field studies, which ICEE is now in the process of designing.

The spectacles are expected to be sold at local shops, schools and health centres for US$3–5 a pair.

Source: www.scidev.net