Science Alert | Here’s What You Need to Know About That Teen Who Went Blind From Eating Junk Food

 

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A poor diet of chips and crisps caused a teenage boy in England to become blind. The boy – let’s call him Jasper – first visited his family GP complaining of tiredness when he was 14 years old. Tests showed he was anaemic with low vitamin B12 levels. He was also a picky eater, but had no problems with his health.

His GP gave him vitamin B12 injections and advice on how to improve his diet. But by the time he was 15, he had started to develop hearing loss and had problems with his vision.

He was referred to an ear, nose and throat specialist and was examined by an ophthalmologist, but no cause was found.

By age 17, his vision had become worse, to the point of blindness. He was referred to the Bristol Eye Hospital when he saw a specialist in neuro-ophthalmology. He was diagnosed with optic neuropathy (damage to the optic nerve) and further tests revealed that the cause was nutritional.

He had several micronutrient deficiencies, including low vitamin B12 (his vitamin B12 injections had lapsed), vitamin D, copper and selenium levels, and a high zinc level. His bone mineral density was also very low – probably resulting from his low vitamin D.

Jasper confessed that he had been a picky eater since primary school and would not eat certain textures of food. He had a daily portion of chips from the local fish and chip shop and snacked on crisps, white bread, processed ham slices and sausage.

Despite being given nutritional supplements to treat his deficiencies, his sight did not improve.

In our case study, published in Annals of Internal Medicine, we concluded that Jasper’s junk food diet and limited intake of nutritional vitamins and minerals resulted in the onset of nutritional optic neuropathy – a dysfunction of the optic nerve, which is important for vision. It is a rare but serious complication of several types of nutritional deficiency.

Deficiencies of vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B6 (pyridoxine), vitamin B9 (folate), vitamin B12 (cobalamin), iron, calcium, magnesium and copper are all known to cause optic neuropathy and are easily misdiagnosed as other disorders if the doctor doesn’t have the patient’s dietary history.

The condition is reversible if caught early. But left untreated, it can lead to permanent structural damage to the optic nerve and blindness, which happened in Jasper’s case.

Adequate nutrition

Nutritional deficiencies are very common, affecting about 2 billion people worldwide.

In low- and middle-income countries, poverty and inadequate food intake are the main causes of micronutrient deficiencies, but micronutrient deficiencies also exist in high-income countries, such as the UK, where they are usually caused by malabsorption (bowel problems that interfere with the absorption of important nutrients in the stomach), drugs, or poor diet – sometimes combined with alcoholism or smoking – or both.

Purely dietary causes are uncommon in developed countries, although picky eating in children can predict picky eating in adults and nutritional deficiencies in later life.

Also, recent trends in food consumption could cause nutritional optic neuropathy to become more common.

For example, the widespread consumption of junk food at the expense of more nutritious food and the rising popularity of veganism can lead to vitamin D and B12 deficiencies, because fish, meat, eggs and dairy are the main dietary sources of these vitamins. Without nutrient supplements or fortified foods, strict veganism can lead to irreversible blindness.

Most of us are aware of the links between junk food consumption and cardiovascular health, obesity, and cancer. Few people are aware that poor nutrition can have such a profound effect on vision.The Conversation

Editor’s note: While the teen has been described as a “fussy eater”, it has been suggested he has a little-known eating disorder called ARFID, or avoidant/restrictive food intake disorder. You can find out more about this disorder here.

Denize Atan, Consultant Senior Lecturer Neurogenetics, Neuro-inflammation and Neuro-ophthalmology, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 

Read out the full version at: https://bit.ly/2lxzYZA

Science Alert | This Photo Is Black And White. Here’s The Science That Makes Your Brain See Colour

 

A bizarre and brilliantly effective optical illusion going viral on the internet tricks your brain into seeing a colour image… but if you look closer, you’ll notice the photo you’re staring at is only black and white.

“An over-saturated coloured grid overlaid on a grayscale image causes the grayscale cells to be perceived as having colour,” Kolås explains on his Patreon page.

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So what’s going on here to make our brains actually interpret this black-and-white picture as if it’s full colour image?

According to vision scientist Bart Anderson from the University of Sydney, the effect we’re seeing in this illusion isn’t particularly surprising.

“The colour system is what vision scientists refer to as ‘low pass’, i.e., many of the receptive fields that code colour are quite large,” Anderson told ScienceAlert.

“So the grids get ‘averaged’ with the achromatic background, which then gets attributed to that part of the image.”

In other words, our brain kind of compresses visual information when we look at things, giving us an overall impression of what’s there if we don’t take the time to examine objects closely.

If you’ve seen this illusion doing the rounds, you might notice this isn’t the main image being shared.

Some of the people in that photo hadn’t given permission for it to be shared online, and Kolås has asked for it not to be used, which is why we’ve put up one of his other examples instead.

The illusion isn’t just created by using coloured grids, either. While Kolås finds grids offer the best effect, he’s also played around with other ways of achieving the visual trick, using alternatives like dots and lines:

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“The raster of dots gives a nice analogy to half-toning as used in print, where colour assimilation aids the optical mixture of colours that already happens before our visual system gets involved,” Kolås explains on his Patreon page.

And here’s an example using lines to create the same effect:

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And another:

Another one, with horizontal lines instead of a grid.

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Most impressively of all, the way this illusion works doesn’t seem to require static images.

In the video below, Kolås shows how even full-motion video with the grid overlay is able to trick the brain into thinking its seeing a colour image, all by virtue of the ‘low pass’ way our visual system attributes colour:

 

To read out more, please visit: https://bit.ly/33feqSB

Science Alert | There’s Something You Really Need to Know About IV Vitamin ‘Shots’

 

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Want to boost your immune system, reduce your physical signs of ageing, or cleanse your blood to get rid of toxins? Intravenous (IV) vitamin therapy, or vitamin drips, promise to help.

Some claim they can even benefit serious conditions like cancer, Parkinson’s disease, the eye condition macular degeneration, the pain of fibromyalgia and depression.

Celebrities have promoted them on social media. The demand has led to alternative therapy lounges popping up around the world, including in Australia. Patients can kick back in comfy leather chairs while they’re hooked up to IVs in the infusion lounge, watch Netflix and have some tea.

But do they work? Or are you just paying for really expensive urine? Let’s look at what the science says.

What is IV vitamin therapy?

IV vitamin therapy administers vitamins and minerals directly into the bloodstream via a needle that goes directly into your vein. Fans of the therapy believe this enables you to obtain more nutrients as you avoid the digestion process.

Providers of these injections say they customise the formula of vitamins and minerals depending on the perceived needs of the patient.

Right now for example, many Australian lounges are offering drip “cocktails” containing immune boosting vitamins like vitamin C and zinc to help protect against the flu. Other popular therapy sessions come under names like “Energy Cocktail” and “Glow”. One vitamin IV therapy session can take 30-90 minutes and will cost between AU$80 to $1,000 (US$55 to $700).

Does IV vitamin therapy work?

IV therapy itself is not new and has been used in the medical profession for decades. In hospitals, it is commonly used to hydrate patients and administer essential nutrients if there is an issue with gut absorption, or long-term difficulty eating or drinking due to surgery.

Single nutrient deficiencies like vitamin B12 or iron are also often treated in hospital with infusions under medical supervision.

But the “cocktails” IV vitamin therapy clinics create and administer are not supported by scientific evidence. There have been no clinical studies to show vitamin injections of this type offer any health benefit or are necessary for good health.

In fact, there are very few studies that have looked at their effectiveness at all.

There is one review on the use of the “Myers’ cocktail” (a solution of magnesium, calcium, vitamin C and a number of B vitamins). But it just contains a collection of anecdotal evidence from singular case studies.

Another trial looked into the effectiveness of IV vitamin therapy in reducing symptoms of 34 people with the the chronic pain condition fibromyalgia. It found no significant differences between those who received the “Myers’ cocktail” once a week for eight weeks and those who did not.

In fact, the authors noted a strong placebo effect. In other words, many people said their symptoms improved when they were only injected with a “dummy” cocktail.

Another study that examined IV vitamin use in fibromyalgia patients was missing a placebo group, involved just seven patients and showed only short-term improvement in symptoms. The only other published study examined IV vitamin therapy use for asthma. But that study was of even poorer quality.

What are the risks of IV vitamin therapy?

Even when it comes to vitamins and minerals, you can have too much of a good thing. For example, if you take in more of the fat soluble vitamin A than you need, your body stores it, risking damage to major organs, like the liver.

IV vitamin therapy “cocktails” also often contain significant levels of the water soluble vitamins C and B. These are processed by the kidneys and excreted into urine when the body cannot store any more. This makes for some very expensive urine.

There is also the risk of infection with IV vitamin therapy. Any time you have an IV line inserted, it creates a direct path into your bloodstream and bypasses your skin’s defence mechanism against bacteria.

People with certain conditions like kidney disease or renal failure shouldn’t have IV vitamin therapy because they cannot quickly remove certain minerals from the body. For these people, adding too much potassium could lead to a heart attack.

People with heart, kidney or blood pressure conditions should also avoid IV vitamin therapy as there is risk of fluid overload without consistent monitoring. The consequences of fluid overload in these patients can include heart failure, delayed wound healing, and impaired bowel function.

What’s the bottom line?

For most of us, the quantities of vitamins and minerals needed for good health can be obtained by eating a healthy diet with a wide range of foods and food groups. Obtaining vitamins and minerals from your diet is much easier, cheaper, and safer.

Unless you have a medically diagnosed reason for getting a vitamin infusion and it was prescribed by your doctor, you are always better off obtaining vitamins and minerals through food. The ConversationTo read out more, please visit: https://bit.ly/2NKIiTo

Emily Burch, Accredited Dietitian/Nutritionist & PhD Candidate, Griffith University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Science Alert | There’s Bacteria Living on Your Eyeball, And It Could Be More Important Than We Think

 

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You may be familiar with the idea that your gut and skin are home to a collection of microbes – fungi, bacteria and viruses – that are vital for keeping you healthy. But did you know that your eyes also host a unique menagerie of microbes?

Together, they’re called the eye microbiome. When these microbes are out of balance – too many or too few of certain types – eye diseases may emerge.

With a recent study showing bacteria live on the surface of the eye and stimulate protective immunity, scientists are beginning to discover the microbial factors that can be exploited to create innovative therapies for a range of eye disorders like Dry Eye DiseaseSjogren’s Syndrome and corneal scarring.

One day it may be possible to engineer bacteria to treat eye diseases in humans.

I’m an immunologist studying how the eye prevents infection. I became interested in this field because humans get only two eyes, and understanding how bacteria affect immunity may be the key to avoiding up to 1 million visits to the doctor for eye infections and save US$174 million per year in the U.S. alone.

Eye microbiome

When discussing the microbiome, most scientists usually think of the gut, and deservedly so; researchers think one colon can harbor more than 10 trillion bacteria. That being said, more attention is now being focused on the impact microbiomes have at other sites, including the skin, and areas with very few bacteria, like the lungsvagina and eyes.

For the last decade, the role of the microbiome in ocular health was controversial. Scientists believed that healthy eyes lacked an organized microbiome. Studies showed that bacteria from the air, hands or eyelid margins could be present on the eye; however, many believed these microbes were simply killed or washed away by the continual flow of tears.

Only recently have scientists concluded that the eye does, indeed, harbor a “core” microbiome that appears dependent on age, geographic region, ethnicity, contact lens wear and state of disease.

The “core” is limited to four genera of bacteria StaphylococciDiphtheroidsPropionibacteria and StreptococciIn addition to these bacteria, torque teno virus, implicated in some intraocular diseases, also counts as a member of the core microbiome as it is present on the surface of the eye of 65% of healthy individuals.

This suggests that doctors should think more deeply about the risks and benefits to the microbiome when prescribing antibiotics. The antibiotics may kill bacteria that are providing a benefit to the eye.

In a recent study spanning more than a decade and including more than over 340,000 patients in the U.S., the authors found that antibiotics were used to treat 60 percent of acute conjunctivitis (pink eye) cases.

But viral infections are the most likely causes of pink eye, and not treatable with antibiotics. More striking, even cases caused by bacteria often resolve in 7-10 days without intervention. It is well known that excessive or inappropriate antibiotic use can disrupt the microbiome, leading to infectionautoimmunity and even cancer.

Discovering an eye-colonizing microbe

Within the past decade, studies assessing the eye microbiome and disease have boomed. They’ve generated an immense amount of data, but most of it is correlative.

This means that certain bacteria have been linked to certain diseases, like Sjogren’s Syndrome or bacterial keratitis. However, whether these bacteria are causing these diseases is still unknown.

During my time at the National Eye Institute, I used mice to identify whether bacteria at the surface of the eye could stimulate an immune response to protect the eye from blinding pathogens like the bacterium Pseudomonas aeuruginosa.

In 2016, ocular immunologist Rachel Caspi at the National Eye Institute and I hypothesized that protective bacteria were living near or on the eye. Indeed, we found a resident bacterium, Corynebacterium mastitidis (C. mast), that stimulates immune cells to produce and release antimicrobial factors that kill harmful microbes into the tears.

Through a series of experiments, the Caspi lab was able to show for the first time a causal relationship between C. mast and a protective immune response. Whenever C. mast was present on the eye surface, mice were more resistant to two species of bacteria known to cause blindness: Candida albicans and Pseudomonas aeuruginosa.

Now, in my lab, we would like to exploit this relationship between C. mast and ocular immunity to develop novel therapies to prevent infection and possibly target more widespread diseases like Dry Eye Disease.

Engineering microbes to improve eye health

The first step toward developing such therapies is figuring out how bacteria colonize the eye. For this, my lab is collaborating with the Campbell Laboratory at the University of Pittsburgh, which houses one of the most extensive collections of human ocular bacteria in the country.

With our unique experimental setup with mice and advanced genetic analyses, we can use this microbial library to begin to identify specific factors required for the microbes to colonize the surface of the eye.

Then, with ophthalmologists and optometrists in the UPMC Eye Center, we are beginning to analyze the immune signatures within the eyes of healthy and diseased patients.

Here, our hope is to use this technology as a new diagnostic tool to target the microbes causing disease rather than immediately treating infections with broad spectrum antibiotics that kill the good microbes too.

Finally, one of our loftier goals is to genetically engineer eye-colonizing bacteria to act as long-term delivery vehicles to the surface of the eye. In the gut, genetically modified bacteria have been shown to alleviate diseases like colitis.

We hope that this new “prob-eye-otic” therapy would act to secrete immune regulating factors, which would limit symptoms associated with conditions like Dry Eye Disease, which affects around 4 million people in the U.S. per year.

In this developing field, there is still much to learn before physicians can begin manipulating the ocular microbiome to fight disease. But one day perhaps rather than just squirting eye drops into your dry eyes, you’ll squirt in a solution with some bacteria that will colonize your eye and secrete the lubricants and other factors your body is missing. Stay tuned. To read out more, please visit: https://bit.ly/2xrx9Mp

Tony St. Leger, Assistant Professor of Ophthalmology and Immunology, University of Pittsburgh.

This article is republished by The Conversation under a Creative Commons license. Read the original article.

Science Alert | Scientists Have Found a Way to Preserve Vaccines Without Refrigeration For Months

 

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Vaccines are only as good as the people they treat and absolutely no good if they are spoiled by heat along the way.

It’s a challenge so great that in some remote parts of the world, this precious medicine has to be transported by camels carrying solar-powered mini refrigerators on their backs. Other populations never get them at all.

The need or an uninterrupted, refrigerated trail of vaccines is known as the “cold chain“, and in most cases requires consistent storage between 2–8 °C, all the way from production to dispersal; otherwise, it could lay waste to the entire process.

“You can spend all kinds of money developing a vaccine, but if it is deactivated by high temperature an hour before you can give it to someone, it doesn’t matter,” says Ali Ashkar, a pathologist who specialises in immunology at McMaster University in Canada.

There are few technical immunisation issues more important, and Ashkar and his colleagues now think they have invented a potential solution, one that could allow vaccines to go unrefrigerated for weeks at a time in warm and remote areas.

While other tactics have focused on reengineering the vaccines or modifying their vectors, this new method is based on the simple addition of sugar.

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In this case, however, the viruses are mixed and then dried into a sugary film, created from a combination of two FDA-approved food preservatives, called pullulan and trehalose.

 

Suspended in this solution, the vaccines can be transported without the need for constant cooling. To reactive them, local clinicians need only add water before administering them to patients, as fresh as if they came from a fridge. To read out more, please visit: https://bit.ly/2WlhtsQ

Science Alert | For The First Time, DNA Has Been Edited With CRISPR in Space

 

The goal wasn’t to create super space yeast. The astronauts were studying how DNA repair mechanisms work in space, so they snipped through strands of the fungus’s genetic code in a number of places to mimic radiation damage.

“The damage actually happens on the space station and the analysis also happens in space,” said Emily Gleason of miniPCR Bio, the company that designed the DNA lab aboard the ISS. “We want to understand if DNA repair methods are different in space than on Earth.”

Space is actually a pretty hazardous place, and radiation is one of the biggest concerns.

Although at its average altitude of 408 kilometres (253 miles) the ISS is still protected by Earth’s magnetic field, in six months onboard, on average the astronauts are subjected to around 30 times the radiation a human receives in a year on Earth.

It’s well documented that space radiation puts ISS astronauts at risk for radiation sickness, as well as raising long-term risk for cancer, degenerative diseases and central nervous system problems.

For a mission to Mars, which would be a lot longer than six months spent outside Earth’s protective bubble, the radiation hazard increases. So figuring out how DNA repairs itself from radiation damage could be incredibly useful.

Humans may not be able to burp properly in space, but we can now edit a genome. For the first time, astronauts aboard the International Space Station (ISS) have used CRISPR-Cas9 to edit the DNA of brewer’s yeast. To read out more, please visit: https://bit.ly/2HYWjqc

 

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