A Bacterial Lunch


The secrets to weight loss may not lie on strange synthetic chemicals or unhealthy new fad diets, but actually in some simple bacteria we’ve known for as long as we’ve been born.

The bacteria in our intestines help us digest the food we intake; from carbohydrates to proteins to fats. But there’s something we humans can’t actually digest: fibre, so instead we use it to push the rest of the food through our guts and prevent constipation. However, since we should eat plenty of fibre, some bacteria use the excess and digest it too, and when doing so, release a substance scientists call propionate. This chemical triggers a reaction in our cells which results in them releasing a specific type of hormones: satiety hormones, such as PYY and GLP-1. As their name suggest, they are used by the body to make people feel ‘full’, by sending messages to the brain telling it to stop eating. In people, it usually takes a decent amount of fibre to trigger this response, so the person has to ingest a large amount of food before this reaction happens.

bacteria lunch

Don’t they look delicious?

But in developed countries, there is an excess of food, so people over indulge and end up over weight or obese. To stop this, scientists have been working with these bacteria in our guts and have come up with a possible solution.

In the form of IPE (inulin-propionate ester), propionate is in a concentration 8 times as large as that of a normal dinner, high enough to trigger the “I’m full” response despite not eating enough fibre. In theory, if a person takes this at some point during the day, they will produce the satiety hormones that will tell the body they are full so the person won’t feel the impulse to eat. The objective of the drug is therefore to reduce weight gain by reducing food intake.

To test this drug, some interesting experiments were carried out. The most curious one consisted of having two groups of people: one taking IPE and one not (the control) face a buffet and an open invitation to eat as much as they wanted (a.k.a. heaven). People with IPE in their system ate 14% less than those without IPE. And if the drug was given to people leading normal lives for six months, those taking the drug ate on average 9% less than those with no drug.

So although eating bacteria’s remains doesn’t sound like the most appealing plate in the book, it could produce long-term improvements in our health.

Smoking Out Y


When people smoke, not only do they inhale burnt pieces of paper which damage their lungs, or have tar accumulate inside of them, which is likely to cause lung cancer, or inject nicotine into their bloodstream, which increases heart rate and blood pressure; it also causes the Y chromosome to eventually disappear. Of course, this only affects males, since the presence of a Y chromosome determines you’re male in gender, but for women smoking is still unhealthy and should be stopped.

Chemicals in tobacco affect this chromosome during cell division or mitosis when the chromosomes are being separated to either sides of the cell. Damage to the chromosome can build up until it eventually disappears. The study, carried out in Sweden, showed that people (men, specifically) who smoked had 33% more chances of loosing their Y chromosome compared to men who didn’t smoke.

However, it has been widely thought for many years that the Y chromosome is so small (in fact, it’s the smallest out of our 46 chromosomes), that its loss wouldn’t have too dire consequences. Past experiments on cells show that they can survive just as well without said chromosome. But new studies show that the lack of this chromosome, although not directly fatal, can shorten life duration and causes an increase in the likelihood of developing cancer. Lung cancer or any other cancer having to do with the respiratory system aside, male smokers are twice as likely to develop cancer as female smokers.

A possible explanation for this is that the Y chromosome contains tumour suppressing genes, so if it disappears, tumours are not going to be controlled and inhibited and therefore will be able to reproduce uncontrollably, causing cancer.

The newest research shows that this effect changes intensity depending on the dose of tobacco smoked. Obviously, the more tobacco you smoke, the more likely you are to suffer from its negative effects. But there’s a silver lining: this process is reversible. If you were to stop smoking, your cells would stop taking damage and after some time they’d be repaired, so you would have the same percentage of healthy cells with a Y chromosome as a non-smoker.

y chromosome

The Y chromosome is more important than you think in the fight against cancer

 

XNA Alternative


DNA and RNA have always been considered miracle molecules thanks to their ability to self-replicate and create life. Everyone thought that they were the only molecules that could carry information on how to code for an organism and pass this down for generations. But what if I told you there were other molecules capable of doing the same thing?

This group of molecules is called XNAs (Xeno Nucleic Acids) and they all are a polynucleotide strands but each with a different repeating monomer. They still have a base and a phosphate group attached; what changes is the sugar in them. Whilst DNA uses deoxyribose and RNA uses ribose, XNA can use a wide variety of sugars, like theorose, or other unrelated chemicals, like peptides.

DNA XNA

This is a normal DNA strand – XNA is the same but with a different sugar in the nucleotide

Not only do they copy the structure of a nucleotide and therefore form a nucleic acid, but they can also store information in the form of bases. However, to make XNA carry bases in a desired order, scientists have to use an enzyme that copies the coding from a DNA strand and passes it onto an XNA strand. Once there, another enzyme can read the bases in the XNA and copy them onto DNA, and if needed, back to XNA. This means that an old XNA can technically pass information to a new XNA molecule, even if it uses an intermediate molecule; this process is basically evolution.

But this discovery is from back 2012. The current news involves XNA being able to act as enzymes, apart from encoding possible genetic information. They still can’t form copies of themselves in the traditional sense, but they can manipulate RNA and even add XNA fragments to an XNA strand. The fact these molecules are enzymes and can modify themselves to some extent makes it more feasible that at some point they will be able to self-replicate, and behave just like DNA did, to evolve into a new type of life.

It is also further proof showing that XNA is a viable alternative to both DNA and RNA, and that the reality that all living organisms we know use these nucleic acids could be arbitrary. In fact, it could be perfectly possible than in other galaxies, organisms use XNAs instead of DNA. Of course, this is only a theory, and we have to take into account the conditions of an environment without any life. RNA and DNA could have developed because they were more likely to appear in the first place, for a reason unbeknownst to us yet.

Genesexual


gene

Although genes could now have a very important effect on men’s sexuality, the environmental impact is still significant

In the largest study on the matter up to date, scientists from Illinois have investigated the DNA of hundreds homosexual men and have found revolutionising results that show that being gay could have a strong genetic influence.

Although the genome is a vast structure, home to thousands of genes, there were two very specific areas contained in it that were analysed in detail. Both these areas have been known by the scientific community for quite some years. For example, one of them, located in the X chromosome, and called Xq28, was first suspected to be related to homosexuality in a smaller study in 1993; whereas the other one, 8q12 in chromosome 8, was discovered in 2005. The aim of this experiment was to confirm these areas had some effect on sexuality in men and investigate how they caused this effect.

Overall, 818 men, all gay, volunteered for this project. This is almost 20 times more people than in the study in 1993. But to make it reliable as well as statistically accurate, many of the test subjects were brothers; in some cases, even non-identical twins! Having two closely related individuals with similar genetic makeup can make differences in their genome stand out and their distinct effect on the phenotype much easier to find. Using DNA collected over many years from blood samples, the scientific team looked closely at these men’s gene sequence. They were looking for small differences in the coding between brothers, specifically for single nucleotide polymorphisms, which are changes of only one base or nucleotide in a gene. After all the DNA samples were analysed, 5 single changes in the nucleotides were observed, and most occurred in these two regions of the genome.

What makes this study’s results worth considering is the fact that the only feature all these men shared was their sexuality: they were all gay. They varied in every other physical feature; so any change in those areas of their genome that was common to all men had to be related to their sexual orientation.

But both Xq28 and 8q12 are filled with genes, so although we know almost certainly that there are genes in there related to homosexuality, there is still not a distinct list of genes that could cause someone to be gay. Finding them hidden in these large areas full of coding is the team’s next task.

This discovery has, as could be expected, grave implications. It could help resolve all discrimination against gay people, and show that their sexual orientation is not a choice, but actually who they are. But unfortunately, it could lead some people to consider homosexuality as a biological mistake or a negative mutation, and even resort to genetic engineering to identify and remove ‘gay genes’ from embryos. This is wrong on many levels, but the most related to this article is that a person’s sexuality is not only defined by their genes, but is also affected by the environment they live in, so changing their genes is unnecessary and would not prevent homosexual people from being born.

Philae Fall


The misadventures of the famous Philae lander have been the hot scientific topic of the week. 10 years of preparation, hard work and effort finally came to fruition when the robot detached itself from the Rosetta Spacecraft after being together for a decade and set off on its journey to comet 67P/Churyumov–Gerasimenko.

philae

How Philae was supposed to look on the surface of 67P

A couple days before the actual separation, ESA, the European Space Agency, which has been supervising the mission all these years; carried out a series of tests to make sure all the machinery in the lander worked perfectly. There was a minor problem with the thrusters, but since there was nothing scientists at Earth could do to fix it, they decided to keep the mission going anyway.

On the 12th of November of 2014, Philae made history when it became the first object to ever land in a controlled manner on a comet. And although this feat is outstanding and impressive by itself, there were some technical difficulties. The idea was that the lander would fire some harpoons to adhere to the comet and use thrusters so that together, they would push the robot towards the comet. But neither of these devices worked as planned, so when Philae did ‘land’, it bounced back. Twice. The first bounce made Philae jump almost 1km high into space (another record), and took the incredible amount of 2 hours for it to fall back. The second leap was much smaller, and only took a couple of minutes for it to settle down. But this was not the last obstacle in Philae’s way. Due to all the bouncing around, the machine ended up about 1 km away from the original landing site, and on top of that, it has stopped in a rather unusual posture. Instead of having its three legs on the pressed on the ground, one of them is dangling midair.

Facing these problems head-on, scientists still tried to carry out some of the proposed experiments. For example, they wanted Philae to take a sample of the comet dust using a drill incorporated into it. This apparatus comes out of the bottom part of the robot, but since Philae is sloping, the drill couldn’t actually reach the ground.

But Philae actually has more pressing problems at the moment. After bouncing all around 67P, it stopped in an area of the comet where the sun rays can’t reach; a fatal location for a solar powered machine like Philae. This soon alerted scientists regarding the duration of the battery, which would quickly run out. The solution was to turn on a ‘power-saving’ mode, but right in the middle of this process they lost contact with the robot. As of the 15th, Philae has used up all its stored energy and has basically shut down. There is still hope that when 67P reaches areas closer to the Sun, the lander will become powered again, but chances are slim.

Regardless of the many problems with the landing and its consequences, Philae did end up on a moving comet, and that’s reason enough to congratulate scientists at ESA for so many years of dedication and a successful mission.

The Potato Controversy


Genetically Modified food has been controversial for many years now, and has a long history of arguments between food manufacturing companies and people against ‘unnatural’ food. The new chapter in this story involves none other than a potato.

Simplot, a company known for its normal and genetically modified potatoes, has created a new product which they call ‘the Innate Potato’, because of how natural it is compared to other GM crops.

To make this potato novel and unique in the GM market, Simplot has created it using RNA interference technology. This method uses RNA strands from other potatoes with different characteristics and mashes them together, to create a sort of Frankenstein Monster potato. The result is much more appealing than the name suggests. By combining many positive qualities from different potatoes, you end up with a potato with numerous benefits. This particular potato, for example, has proven resistant to bruises, and produces fewer carcinogens when fried. Usually, when normal potatoes are fried, the amino acid asparagine can react to form acrylamide, a suspected carcinogen. When tested, Innate Potato produced up to 75% less acrylamide when heated.

mcfries

Someday in the future, it is possible that McDonalds fries are made from genetically modified potatoes

Not only that, but since it only uses genes from natural potatoes, and doesn’t use genetic material from other species like bacteria, it is immune to many of the usual complaints of GM-haters, which dislike the idea of mixing genes between two opposite species.

In spite of the strong opposition, the Innate Potato has already been approved by the USDA, (the Unites States Department of Agriculture), so it could potentially be sold to customers anytime now. In fact, rumour has it that McDonalds, one of Simplot’s biggest customers, might use the potato in the near future to make their well-known McFries. This, of course, has caused a heated debate where some opposers of these potatoes are pressuring the fast food company to reject them. McDonalds’ decision concerning this matter is still unknown.

However, Simplot only plans to grow a limited number of these super potatoes for now, so regardless of McDonalds’ decision we’ll probably have to wait quite some time to taste them.

Until then, McFries are still delicious.

Plant Sun Cream


We’ve all spent a little too much time on the beach and gotten sunburn: when our skin gets red and aches. But have you ever wondered how plants, which spend their whole life sunbathing, never get burnt? Scientists in Indiana asked themselves this same question and here’s what they found out.

For a plant to survive, it needs to carry out photosynthesis, which uses ultraviolet light as energy to drive the whole process to completion. But UV radiation is also what harms us and causes sun burns. There is an obvious problem here, because how can plants absorb UV for photosynthesis but also block it to remain healthy? This is a bit of a trick question, as there are many different types of ultraviolet radiation depending on the frequency, each one with its own properties. The one we’re interested in today is UV-B since it is the one that commonly causes sunburns.

plant sunlight

Light can be dangerous, so plants have developed a mechanism to both utilise light but protect themselves from it too

It’s been known for a while that a group of molecules, called sinapate esters, are found on a top layer of plant epidermis, and their abilities include absorbing light energy for photosynthesis and blocking the harmful frequencies. Now, these seem like the answer to the question I posed before, right? Yes, but until now, scientists, although they knew their effects, didn’t know precisely how they worked.

Here’s when the team at Indiana, lead by Timothy Zwier, come into the picture. They decided to investigate sinapoyl malate, a certain sinapate ester that can do most of the radiation absorbing by itself. To find out what frequencies this chemical absorbed, they went through a very interesting process. It starts by cooling a sample to close to O degrees Kelvin, or absolute zero. This causes it to become gas molecules, which can be kept functional if they are surrounded by argon gas atoms. Then, a UV-B laser is shot at them and the frequencies absorbed and transmitted are ready to be measured.

The results were absolutely fascinating. This small little molecule, when covering a leaf or any plant structure, can absorb the whole of the UV-B spectrum of light, effectively blocking all common harmful light. By doing this, the interior of the plant is left unharmed and protected form the adverse effects of radiation, including mutations in the fragile DNA sequence.

It is a truly effective method, since plants are exposed to sunlight all day long and are never burnt, so some possible applications of this substance include the production of suntan lotion for us humans lacking godly molecules on our skin, or creating even more UV-protected plants in case of increased UV radiation, like that caused by the disappearing ozone layer.

 

If you want to read the article: http://pubs.acs.org/doi/abs/10.1021/ja5059026

Chocolate Memories


Everyone loves a good cup of hot chocolate, except those weirdos who don’t, but now it seems this tasty treat could actually have tremendous benefits other than its deliciousness.

hotchocolate

What’s not to like?

Memory deficit usually comes hand in hand with old age. To shed some light onto this problem, scientists at Columbia University carried out an experiment on volunteers aged 50 to 69. These people were divided into two groups; one was given normal hot cocoa, whilst the other was given the same beverage but with increased amounts of flavanol. Flavanol is a chemical commonly found in chocolate, but which also appears in vegetables, fruits and even tea.

Before the investigation started, the patients had an MRI scan taken, and went through a memory test. In it, the volunteers were shown a group of about 40 shapes, and after a minute, they were shown a larger group of shapes, in which they had to recognize the previous ones. During the three months the study lasted, they were given two cups of the drink every day. After this period of time, MRI scans were taken again and the subjects repeated the test.

The results were astonishing. After being given this high-flavonol diet, the patients of the study had improved their memory by a highly considerable amount. It had even become similar to that of a person 30 years younger, as shown by the memory test. The MRI scans also revealed some striking information. There was an increased blood flow in the dentate gyrus of the patients, an area of the brain in the hippocampus, by almost 20%, which had been previously related to memory problems in elderly people.

But if you’re between 50 and 69 years old, don’t start stuffing yourself with chocolate. The flavonol content of those drinks which enhanced memory was of 900mg, which is 90 times as much flavonol as a normal chocolate bar. However, it is still an interesting discovery, which most scientists agree should be investigated further, in greater trials, and with more variables considered.

Paralysis Cured By A Nose


Paralysis is a terrible condition suffered by over 3 million people, but can actually affect anyone and has very few solutions. In an almost miraculous turn of events, this has now changed thanks to scientists, doctors, and curiously enough, a chef.

David Nicholls is a world-known, Michelin Starred-chef whose son Daniel became paralysed in an accident in 2003. Since then, he has tried everything possible to help his son, including creating the Nicholls Spinal Injury Foundation (NSIF) which aims to raise awareness of paralysis and fund any promising cure projects.

Spinal surgery breakthrough

Darek Fidyka, showing the extent of his recovery

One of these donations was used by a team of researchers at UCL to pioneer a mechanism for nerve regeneration in spines. They were lead by Professor Geoffrey Raisman, a scientist with a long history in nerve cell innovations. He was the discoverer of ‘plasticity’, a quality our bodies possess by which damaged nerve cells can regenerate. Although this idea was controversial at first, it eventually opened the door for possible repair treatments.

His newest brilliance involves implanting cells from the nose to the damaged area in the spinal cord. But this doesn’t work with any nose cells. It specifically requires OECs, which stands for olfactory ensheathing cells, and their role is to repair broken nerve cells in the nose so that communication between these and the brain is restored, and our sense of smell works correctly.

This idea was applied by a group of doctors in Poland, lead by spinal repair expert Dr Pawel Tobakow, with surprising results. The patient they treated was Darek Fidyka, a man who was stabbed in the back so his spinal cord was cut in two, leaving a gap with severed nerve cells. The operation consisted of implanting Fidyka’s OECs into the gap where these, instead of healing nose nerve cells, would bridge the separated spinal nerve cells so given time and the appropriate rehabilitation, the spine would no longer be divided into two.

And so it happened. Two years later, the nerve cells on either side of the cut have regenerated and the connection between these has been re-established, effectively ‘curing’ the paralysis. The changes to Fidyka’s life have been enormous. Weeks ago, he wasn’t even able to feel his legs. Now, not only is he regaining some feeling, but can also walk and is even capable of driving a car! More patients are waiting to be treated with this method in hopes of recovering from this horrendous condition and to prove this treatment effective enough so even more injured people can be cured and the fullness of their lives restored.

Nobel Prizes 2014: Part 2


Today, with Jean Tirole being awarded the Economics Nobel Prize, was the last day of the Nobel Prize award season. Last week, we looked into the winners for physiology and physics, so we still have one scientific award to investigate: chemistry.

The 2014 Nobel Prize for Chemistry went to… Eric Betzig, Stefan W. Hell and William E. Moerner for “the development of super-resolved fluorescence microscopy”.

Microscopes are a valuable tool for all scientists, from physicists examining subatomic particles to biologists investigating cells. But for many years, it was believed that microscopes were limited in how much magnification they could provide. The smallest they could go was 200 nanometres, or at least that was what they though until these laureates came along. The key to their innovation was brought by the use of fluorescence to increase resolution.

Hell created a mechanism called STED (Stimulated Emission Depletion) to take higher resolution pictures which involved laser lights. As an example, he used an E. coli bacterium coated with fluorescent molecules and a special microscope which emitted two tiny rays of light. One of these excited some molecules so certain parts of the bacterium glowed, whilst the other did the opposite, and made the sample duller. This might seem contradictive, except the centre of the convergence was left to shine, so only a small area was illuminated. A picture was then taken of the glowing part, and the procedure repeated at many angles. Combining the pictures taken, he was able to form an image of an unprecedented resolution.

microscope

Imagine being able to look deeper into cells – it’s possible now thanks to this year’s Chemistry winners

This is close to what Moerner and Betzig did. They used fluorescent proteins, which could be activated by short pulses of lights. They shone these onto a different part of the sample every few milliseconds, so they only glowed for a short period of time. By superimposing the images of the lighted parts, they were able to capture individual molecules in images! This amazing method is now called single-molecule microscopy and has been used in a wide variety of studies, from HIV research to gene modification.

Thanks to these men’s work and dedication towards science, we can now see deeper into our world than we have ever done before. A few years ago, we could only look at individual cells, never inside of them. But now, we can actually see what they contain, into their small organelles like mitochondria and the Golgi body that allow cells to do all the complex processes that keep us alive. Not only this, we can actually investigate individual molecules from chemicals, advancing the field of chemistry. Their contribution to our knowledge pool is immeasurable, both directly and indirectly, and for this, they are well-deserving of the Chemistry Nobel Prize.