Archive for Recent Research

Toothbrushes and breath testers for tuberculosis

// January 15th, 2013 // Comments Off on Toothbrushes and breath testers for tuberculosis // Recent Research

Far-advanced tuberculosis diagnosed by x-ray. Image from the CDC, accessed on Wikipedia.

Tuberculosis is a major health issue, with around a third of the world’s population infected with the bacteria mycobacterium tuberculosis. Not all these people actually have signs of illness, only 10% will go on to have any symptoms during their life. For the rest it remains latent, the bacteria is present but not causing any problems.

As tuberculosis is only contagious and dangerous when it’s active, that’s usually what people test for. Chest x-rays can check whether TB has affected the lungs, and are required for people travelling from high-TB countries to low-TB countries including Australia and the United Kingdom. The other avenue for diagnoses is the slightly grosser method of analysing the gunk people cough up, to see if there’s bacteria in it. For  mycobacterium tuberculosis, growing a sample in agar takes weeks.

A breath test would be a much safer and faster way to see if bacteria are present in the lungs, and that’s what our first paper is looking at. Researchers from the University of Vermont are finding out whether bacteria can be identified by their “chemical fingerprint,” a cocktail of chemicals that makes its way from the lungs to the breath. Their research is published in the Journal of Breath Research.

Now, it’s some time before police can pull you over for a quick TB test when you’ve been swerving off the road from a coughing fit. “Honestly, it’s just the flu!” But it’s got to be a cheaper option for many countries with low health care budgets.

TB poster, image from Wikipedia.

It is early research. They studied the tiny puffs from mice, rather than humans, and looked at two different bacteria that cause lung infections Pseudomonas aeruginosa and Staphylococcus aureus (Golden staph), neither of which are the TB bacteria. Clearly there is more research to be done, but it’s a promising start.

Read more about it here.

TB can be cured with a course of antibiotics, or more specifically a combination of several antibiotics that have to be taken for six months. Like Golden Staph, the bacteria that causes tuberculosis is becoming increasingly drug resistant. Drug resistant strains need different antibiotics and take 18 months or more to cure.

In Papua New Guinea, extensively drug resistant TB is a problem. A recent outbreak there and movement of patients to better health facilities in Queensland and the Torres Strait Islands has triggered alarm and, frankly, scaremongering media reports and political backlash. You can read about it on the Conversation, because I’ve been out of Aus too long to be in on the goss (but I’m back in a month, yay!)

The next weapon against drug resistant TB may come in the unlikely form of a traditional toothbrush. The South African toothbrush tree contains a compound called diospyrin, which inactivates an enzyme critical for bacteria reproduction (but does not affect the similar enzyme found in human cells.) The enzyme is a DNA gyrase… would you care to know how it works?

When DNA is replicated, the two strands normally joined in a double helix are broken apart, and you can imagine it’s like putting your fingers into a rope and pulling apart the strands. If this imaginary rope is a circle (as DNA in bacteria is) then it can’t just unwind itself at the ends. Instead, things will get messy, and the DNA will coil and twist up on itself. These “positive supercoils” are a bit like like twisting a shoelace until it bunches up, and is bad for the DNA. Gyrases relax the positive supercoils by cutting the DNA and moving one strand to the other side, then joining them up again.

Circular DNA supercoiling. Image by Richard Wheeler.

Circular DNA supercoiling. Image by Richard Wheeler.[/caption]

By stopping gyrase activity, the bacteria can’t replicate its DNA. The research by a team from the UK and South Africa described how this compound from the toothbrush tree interferes with gyrase, and importantly, that it acts in a different way to existing antibiotics. This will hopefully be a chink to exploit in the armour of drug resistant bacteria.

Here’s the paper from the Journal of Biological Chemistry and the press release.

New species of supercute slow loris

// December 15th, 2012 // Comments Off on New species of supercute slow loris // Recent Research

Slow loris species can be identified by markings around their eyes and head. Image by Helena Snyder. Wikimedia commons

With huge eyes peering through a bundle of fluff, slow lorises are the epitome of adorable. Just look at that face!

And that’s just what scientists have done – looking at the facial markings of slow lorises to identify one completely new species, and officially recognising two more as unique which had previously been considered possible sub-species.

The distinctive markings that separate the species include the mask-like patterns around the eyes and varying shapes of cap on the head. The newly described species, Nycticebus kayan, is named after a river running through their habitat in Borneo.

It’s their toxic bite that makes slow lorises unusual among primates.

More unusually, the toxin isn’t produced in the mouth but in glands on the arm. Licking or nuzzling the gland, they mix the toxins with their saliva to create an irritant.

Not only do they use it for defending themselves, but they also spread their spit onto their young, protecting them too.

Bit like a grandparent spitting on a napkin to rub the dirt off your face. Except afterwards you have AWESOME TOXIC POWERS! Still gross though.

The new Kayan species, notice the different markings around the eyes and cap to Bengalensis, above.

Unfortunately, lorises are endangered due to habitat destruction and the fact that they’re so damn cute, everyone wants them as pets. Illegal animal trade has taken a toll.

Still, it’s hard to imagine an animal like this going extinct. Insects and spiders, you know, they just haven’t got the same marketing department. Although, having said that, snow leopards are beautiful as well, and it sounds like they’re close to going extinct in the wild, so you never can tell.

Thinking about endangered animals makes me so sad! I saw a David Attenborough documentary a few days ago about his life and how the planet has changed and a couple of species had gone extinct since he saw them. Just made me feel a bit crap for being a human.

Still, even Attenborough did some silly things when he was young (like eating a clutch of sea turtle eggs), and his work has probably saved thousands of animals by now. People change.

So there’s always hope! Because a world without slow lorises in it… well, it’d be no kind of world at all.

More info at Wiley press releases.

Powering devices with the battery in your ear

// November 10th, 2012 // Comments Off on Powering devices with the battery in your ear // Recent Research

Mammals have natural batteries within their ears. Image by אני, CC license.

Did you know there’s a battery in your inner ear? It was news to me when I found this on Turns out not only is there a natural battery, but a group is working to utilise it to run medical devices.

The natural role of your ear battery is to turn sound vibrations into electrochemical signals, which travel down nerves to the brain. An imbalance of sodium and potassium ions (as with nerve cells) is created using cells that pump ions back and forth across a membrane – this is the battery.

It’s crucial for good hearing, and could be tapped to power devices.

Though it is very low voltage, the team was able to harness a small proportion of the natural battery to power a radio transmitter. In the future, this transmitter would be coupled to a sensor, and send data about how the ear is performing to a nearby computer.

During the experiment they used a guinea pig (literally) as a substitute for a human ear. The guinea pig responded normally to hearing tests, even with the implant. The chip itself was located outside of the guinea pig’s ear, but would fit inside a human’s middle ear cavity. We have got bigger ears than guinea pigs, after all.

They estimate it would take between 40 seconds to four minutes to build up enough juice to run the radio transmitter, but after that it keeps itself going.

To get around the lag time, they could send a burst of radio waves to provide that initial power – a kick-start.

It’s one of many developing technologies to explore new ways to tap into existing energy. Cell phones that can power themselves from the mechanical vibrations of being tapped, touched or carried are also in the pipeline. Rolex has been powering its wristwatches for decades using movement energy it collects when worn.

This research could open new ways to study the inner ear for people with hearing difficulties or problems with balance. It could also provide treatments, such as by improving hearing aids. All with the battery in your ear!

Oh no, it’s been so long since my last update!

// October 14th, 2012 // Comments Off on Oh no, it’s been so long since my last update! // Recent Research

Oh dear, I’m seriously struggling to keep up this blog at the moment. Europe is just so distracting! So many pretty things to see and history to learn, when I get home I usually just zonk out and berate myself silently for not having the strength to blog.

I did see another cool clock today, it was a sphere with the daylight hours in gold and the nights in black, and it had a circle marking the seconds, the hours, and the day of the week (at least, I think that’s what it said – it was in Czech.)

I’d appreciate any advice on how to keep this blog cooking while I’m so distracted by things. Should I write short articles about things I see that are sciencey (like the astronomical clocks), or start a google alert and write about ever mention of one specific topic – leprosy, maybe? Dinosaurs? Ancient medical treatments for gout?

Anyway, a lot has happened since I’ve been galavanting in Germany and the Czech Republic, such as the Nobel Prize Ceremony. Woo! Only the biggest science event of the year, tiny thing like that, you might not have heard about it.

I was really pleased to hear the Nobel Prize for Medicine going to the people who showed how to turn adult cells into embryo-like stem cells. What a brilliant way to dodge a tricky ethical issue! Mushing up embryos to treat other humans is some shade of grey, so why not take the cells from a consenting adult! An added bonus, you can take cells from a sick person, transform them into stem cells, then use them back into the same person – no organ rejection.

The physics one was so fitting, because it was for for “ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems”, and quantum optics is such a vast and growing field. I feel like it will be the future of computing, it has that same latent excitement that I imagine early computer scientists would have felt decades ago. If there’s anything I should tag on my google alerts, it should be quantum computing and optics.

The Nobel Prize for Chemistry was awarded for studies in G-protein-coupled receptors, a group of receptors that allow cells to sense their environment, picking up sensitive chemical cues like smells and tastes. According to the press release, half of all medications work by triggering G-protein-coupled receptors.

On a non-science note, the Nobel Prize in Literature was awarded to Mo Yan “who with hallucinatory realism merges folk tales, history and the contemporary.” Sounds really cool! I haven’t read any of his work, but I’m pretty keen. It sounds similar to the magical realism in Like Water for Chocolate.

Well, I have to go pack my bags now! Moving towns again, and have a train to catch in the morning. I’ll try to do better and update more often! Any advice/support really appreciated 🙂

Brains compensate for a stuffy nose

// August 13th, 2012 // Comments Off on Brains compensate for a stuffy nose // Recent Research

Image by Miguel Angel Pasalodos, licensed on Creative Commons CC BY-SA 2.5

Nothing like a stuffy nose to ruin your day. You sound like a ponce, food tastes like cardboard and you have to sleep with your mouth open for spiders to crawl in. No joke. It happened to a friend of a friend of mine.

But have you ever noticed how quickly your sense of smell returns? Almost as soon as the sniffles are gone, you’re back to sniffing roses, and new research is finding out how our brain can adjust so fast to changes in sensory input.

What I love about this study is how they did it.

For a whole week, 14 people had their noses completely blocked during the day. At night, they slept sans-nose-blockers in a special low-odour hospital room.

A low odour hospital room? All the ones I’ve been to smell weirdly like custard. I wonder if all 14 shared the same room, or if they were spread out… I mean, even if you do have a spesh no-custard hospital dorm, if 14 people spending the night there it won’t be low odour for long.

Brain activity in response to odours changed after a week of smell deprivation in two regions. Activity increased in the orbital frontal cortex, but decreased in the piriform cortex, both are related to our sense of smell.

“These changes in the brain are instrumental in maintaining the way we smell things even after seven days of no smell,” said lead author Keng Nei Wu, Northwestern University Feinburg School of Medicine, in the press release.

“When your nostrils are blocked up, your brain tries to adjust to the lack of information so the system doesn’t break down. The brain compensates for the lack of information so when you get your sense of smell back, it will be in good working order.”

Once the 14 participants were released to sniff wildly, their brains soon returned to normal, showing pre-experimental levels of excitement when offered something smelly.

This rapid reversal in the realm of smell is quite different to sight, where deprivation usually has longer-lasting effects. Wu suggests this could be because smell deprivation is pretty common, given our penchant for catching colds and having allergies. Perhaps it has evolved to be more agile, or perhaps the endless sniffles we get in primary school gave our brains ample chance to practice.

Either way, it seems the quick adjustments by our brains protect our sense of smell, so it can rebound quicker than you can say “the one who smelt it dealt it.”

Wu ends by saying “more knowledge about how the system reacts to short-term deprivation may provide new insights into how to deal with this problem in a chronic context.”

Chronic loss of smell is nothing to be sniffed at (lol.) It really takes the fun out of life. This column, 20 years of living without a sense of smell, was clearly written from the pits of despair for want of a whiff of fabric softener.

ResearchBlogging.orgKeng Nei Wu, Bruce K Tan, James D Howard, David B Conley & Jay A Gottfried (2012). Olfactory input is critical for sustaining odor quality codes in human orbitofrontal cortex
Nature Neuroscience : 10.1038/nn.3186

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