Chemistry World Podcast - February 2007

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Brought to you by the Royal Society of Chemistry, the Chemistry World Podcast.

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Interviewer - Chris Smith 

Hello and welcome to episode 5 of the Chemistry World podcast with me Chris Smith, with Editor, Mark Peplow... 

Interviewee -Mark Peplow

Hello!

Interviewer - Chris Smith

And science correspondents, Victoria Gill... 

Interviewee -Victoria Gill 

Hello!

Interviewer - Chris Smith

And Richard Van Noorden... 

Interviewee - Richard Van Noorden

Hello!

Interviewer - Chris Smith

This month:   Good news for any Poky Pooches.

Interviewee - Richard Van Noorden

Is your dog too fat, you might be able to cure that problem with a new doggy pill called Slentrol and that's just been approved for the management of canine obesity.

Interviewer - Chris Smith

Also life on a restricted carbon diet.

Interviewee - Helen Pilcher

For a week, I lived on a carbon budget and this was to do some research into an idea that had some scientists had proposed as a way to trying to get us to reduce our carbon dioxide emission.

Interviewer - Chris Smith

Find out how Helen Pilcher got on her carbon-restricted lifestyle later on in the program.   Also, has the death penalty in the US got very long to live?

Interviewee - John Sheldon

You will shut us up quite quickly if you'd simply give the same courtesy to an inmate that you would give to a dog that is, use a logical, tested protocol with people who are trained to give it.   That's all coming up shortly.

Interviewer - Chris Smith

Now listeners to last month's Chemistry World podcast will recall Petro's painful question about bruises.

Interviewee - Petro

I'd just like to know why bruises are the colour they are and why do they change colour every time.

Interviewer - Chris Smith

We'll be hitting you with the answer later.   First though, I shall I have to learn to take my tea black then, Mark.

Interviewee - Mark Peplow

Yeah.   This is a nice little story, Chris.   Basically it's been long suggested that tea has health-giving properties and in the last few years, there's been plenty of studies done to actually work out the chemistry of how that happens, but now new research from Germany has found that if you add milk to your tea, it actually removes those health-giving benefits.

Interviewer - Chris Smith

Do we know why it's good for you without the milk?

Interviewee - Mark Peplow

Yeah! People have been able to pin down at some of the key compounds in tea and there are called catechins.   These help to relax and expand blood vessels.   Basically they promote nitric oxide in the blood and that helps to loosen the muscle around arteries, it can help reduce the risk of clogged arteries and heart disease.

Interviewer - Chris Smith

So why should adding milk to the tea affect that?

Interviewee - Mark Peplow

Well, basically there are proteins called caseins in the milk which wrap themselves around these useful tea catechin molecules and stop them interacting with the enzymes in your body that are helping to relax the blood vessels.

Interviewer - Chris Smith

So, what are the, sort of, Tea Information Council advocating then, that we encourage people to try and get used to black tea, rather than milky tea?

Interviewee - Mark Peplow

Well, I don't about the Tea Information Council, but certainly the head researcher that did this work, Verena Stangl, certainly drinks her own tea black, that's purely because she prefers the taste to be honest, but she does say that's it's worth investigating whether adding milk affects any of the other properties that tea is said to have.   For instance, some of the other compounds in there are antioxidants which are supposed to help reduce the effects of ageing in our bodies and she says it's essential now to actually look at what milk proteins are doing to those compounds as well.

Interviewer - Chris Smith

Isn't it a potential confounding fact that milk, in some instances, contains a lot of fat and so you're getting a lot of covert calories and lot of potentially saturated fat in with your tea that you are drinking and we know they provoke arterial disease.

Interviewee - Mark Peplow

That's true.   Although I might, you know, a splash of milk in your tea, I can't imagine that it would make a huge difference to your overall daily fat intake.   I think one of the things that I take from this is that, whenever you read a study saying, yeah, we found this great compound in wine or chocolate, it's great for you and everyone takes the message from that, I should drink more wine or eat more chocolate.   I think what we got to remember is that all the chemicals in food are interacting with all the other chemicals that you are eating and drinking at the same time, so it's often very difficult to predict what the effect of a particular chemical will be in your food.

Interviewer - Chris Smith

Now talking about staying healthy and reducing your risk of heart disease, it turns out that in America, Richard, Pfizer have achieved FDA approval for a fat-busting drug not for humans but for dogs!

Interviewee - Richard Van Noorden

Well, Chris is your dog too fat, you might be able to cure that problem with a new doggy pill, its called Slentrol, which is the brand name for the dirlotapide and that's just been approved for the management of canine obesity.   The drug works by probably decreasing the amount of fat that your dog can absorb from the food it takes in.   It may also stimulate the release of hormones that causes the dog to feel full.   The drug was actually initially tested on humans, but it caused so many side effects, vomiting, diarrhoea, and it just wasn't suitable for humans.   So now they've done it for dogs who apparently can take the side effects more happily.

Interviewer - Chris Smith

I was going to say because it doesn't sound like it would be terribly pleasant to be an owner of a dog that's suffering those side effects if you get my drift?

Interviewee - Richard Van Noorden

Yes, while they have still some vomiting and diarrhoea, but apparently to much lesser extent, so it's all okay.

Interviewer - Chris Smith

So when is this going to kick off or are owners already dosing their dogs?

Interviewee - Richard Van Noorden

Well Pfizer says they are going to market in the next few months, that's quite soon actually.   It's given in liquid form and it will cost you between 1 and 2 dollars a day for your dog.

Interviewer - Chris Smith

But I don't understand this.   Because the one thing it's easy to do with the dog is to put in on a diet.   I mean, humans suffer a problem with self-efficacy and controlling what they put in their mouth, but since you've got to open the tin of meat to give to the dog, surely there's less of an issue here.

Interviewee - Richard Van Noorden

Exactly, and some people are saying and I agree with them that people who are treating their dog as part of the family, so now the dog is like a human being and you're feeding it when you are eating and if you are overeating the dog is overeating and if you are curing your overeating by trying to take a pill or some detox diet, then so should the dog.

Interviewer - Chris Smith

I still think a good walk and eating a bit less is going to be an easier answer.   Surely, the price tag alone will deter owners.

Interviewee - Richard Van Noorden

Well, I would think so too, Chris, I agree with you.   But remember that some 10% of dogs in the US are classed as obese.

Interviewer - Chris Smith

Do you think unscrupulous owners might be slipping it into their slightly obese partner's food in an attempt to slim them down too?

Interviewee - Richard Van Noorden

I hope not because it does say on the drug that it's certainly not suitable for use in humans.

Interviewer - Chris Smith

And any signs that it's coming to the UK?

Interviewee - Richard Van Noorden

I'm sure Pfizer will want to market it in the UK, but they haven't said so yet.

Interviewer - Chris Smith

Its not just dogs, is it?   What about cats and other animals; there are all these pets that are showing record levels of obesity now.

Interviewee - Richard Van Noorden

Yeah.   In fact, cats respond to the drug quite differently from dogs and it's not suitable for use in cats at all.   So we're going to have to look rather carefully if you want to find tailored pills for every single pet.

Interviewer - Chris Smith

Certainly food for thought, if nothing else, thanks Richard.   And now from cutting calories to cutting carbon dioxide; Helen Pilcher's been finding out what it is like to survive on a low-carbon lifestyle.

Interviewee - Helen Pilcher

For a week, I lived on a carbon budget and this was to do some research into an idea that some scientists have proposed as a way of trying to get us to reduce our carbon dioxide emissions.   So, basically it's called carbon rationing and the idea here is that if this scheme is to be introduced, everybody in the UK would be given an allocation of carbon credit and these correspond to the amount of carbon dioxide that's released into the air, so every time you flick on a light switch, every time you boil a kettle, you are releasing CO2 and under this scheme, you'd be given a number of credits that every time you purchase fuel or energy, a certain number of credits will be deducted and the idea is that you have to live within a particular budget and every year the government sets that budget, gives you your carbon credit and then you will be able to use it bit by bit, so that gradually and collectively, we all start steer up this climate change and decrease the amount of greenhouse gases that we are mixing into the atmosphere.

Interviewer - Chris Smith

The target is 60% reduction by 2050.   Do you think it's achievable?

Interviewee - Helen Pilcher

Well, it's interesting.   Yes I think it's achievable, but only if everybody does that bit and to get everybody do that bit you need a really conservative motivation, you need people to know about the different ways of decreasing their CO2 emissions, you need better education about this in schools, you need not just political talk behind it, but you need political action behind it.   And there are a number of politicians who are counting this carbon budget, carbon rationing scale as the fairest and most practical way to achieve this 60% reduction target.

Interviewer - Chris Smith

Was it a painful experience though Helen, having to exist like this, must've been a shock?

Interviewee - Helen Pilcher

Well, it was and it wasn't.   I had a bit of time to think about it.   So, basically what I did was live normally for a week and work out how much CO2 my household chucked out during that week and that's so easy to do.   You just take a couple of meter readings, you take electricity, you take gas and then there is some very helpful calculators on the internet, you plug your figures into the internet, into these calculators and they tell you how much CO2 you spluttered out.   Then the next week I tried to reduce that figure by 60%.   Now obviously that's a much great reduction that would be happening year on year in this scheme but it was to try and see if I could live as we would be in the year 2050.   Now there are a number of different things I did.   The most immediate thing that we can all do to really slash the amount of CO2 that we emit is to stop going in a car to zip down the road to buy milk.   I stopped using my car, well I could, I didn't abandon it, but me and my little girl start getting the bus everywhere.   Now she is 2, she thought that was the most fantastic thing, even when it was absolutely tipping down with rain, she loved it.   For me carrying her, the buggy and six bags of shopping, it wasn't quite so funny but it gives you a massive save in the amount of CO2 that you splurge out and then there are loads of other little things that you can do and the little things aren't a hardship at all; things like turning your lights off, fitting energy-efficient light bulbs, turning down your furnace down by a degree.   They're all very simple changes that we've all heard off, but we never quite get around to doing, because it's sort of comfortable living in your house as they are, but collectively if we all do them, they can make a really big difference.

Interviewer - Chris Smith

What about food, is that included in the budget, because carting things around the country from one end of the country to the other often just water, the most abundant thing on the surface of earth, eating meat, you know, your rearing livestock, which produces huge amounts of methane and also huge amounts of CO2, this is going to contribute to global warming.   Are there are other lifestyle changes that we could make in terms of our diet to cut CO2.

Interviewee - Helen Pilcher

Well, now that's a very good point.   Under this carbon rationing scheme that I lived in, it's just one variant of a number of schemes that are being proposed.   The carbon rationing scheme that I lived on looked at energy and fuel alone.   But there are variants of this scheme that take it one step further and they look at all products and services.   So, that means there is a CO2 cost associated with buying a tin openers or, buying a tin of tomatoes, staying at a hotel, having a haircut, but how do you workout what that is.   And I think basically as consumers push towards one thing, more information about the CO2 cost with their products then these kinds of things will become easy.   For example, Boots the chemists -- pharmaceutical company are developing a low CO2 shampoo and I think probably what we'll see 5 to 10 years down the line is that when your are choosing your products off the shelf in a supermarket, you know, next to organic and free range, you'll also have CO2, so that you'll be able make a lifestyle decision because undoubtedly things like air miles and food miles are also contributing a huge amount to the amount of CO2 that's causing this climate change problem.

Interviewer - Chris Smith

Science writer, Helen Pilcher, and you can read Helen's article in this month's Chemistry World, which is on the web at chemistry world dot org.   Now we heard last month that nanoparticles could be the demons of environmental pollution.   But now you're telling us, Richard that they could help to iron out wrinkles in the skin too.

Interviewee - Richard Van Noorden

Another cosmetic spin-off from nanoparticles extensive lists, this one suggesting that nanoparticles could be used in skin to stop wrinkling.   Nanoparticles already marks it in creams to stop your skin looking stiff and wrinkled and that's because they can help distribute vitamins deep beneath the skin and sort of plump it up, but this is a different approach.   Ilsoon Lee of the University of Michigan US and his colleagues suggest that nanoparticles could stop your skin ever wrinkling in the first place.

Interviewer - Chris Smith

So what's the basis for doing this?   How does it work?

Interviewee - Richard Van Noorden

Well, the team were actually working on thin polymer films which are used in, say computer display screens, and if you get wrinkles in these films during processing that can affect the performance of the films, so Lee's team were trying to stop the wrinkling and they did that with silicon nanoparticles.   You put them in layers of the films and the idea is they think, that when the sides of the films get stretched through heating or mechanical processing, the nanoparticles somehow redistribute the stress above, below, out of the plane of the film, and stop the film wrinkling up.   The reason it might work on skin as well is that both skin and the thin film are similar system.   Skin consists of a thin layer, the epidermis on top of the much thicker layer, the dermis and the thin films used in your say TV screens are also a thin polymer layer on top of some inert substrate support, which is much thicker and the reason that thin films wrinkle when they're being pushed is that the thin film stretches out and the interface between the thin film and a thicker substrate means the two react in different ways and one wrinkles over the other.   In the same way that dried fruits, sort of, wrinkle out when the thin outside stiffens over the soft inside.   And because that happens in your skin as well, when your skin ages and the outside thinner bit gets stiffer, it's thought that if you could put these nanoparticles in your skin, they might stop that stiffening occurring in exactly the same way as they stop the film wrinkling.

Interviewer - Chris Smith

But they presumably have to be there continuously to do that?

Interviewee - Richard Van Noorden

Well exactly! And Lee did say, of course we are not suggesting that someone will necessarily bombard their skin with nanoparticles, although there are people already injecting their skin with poison, Botox, to stop their skin wrinkling up, there's no questioning what people might do, but Lee thinks it might find use in artificial skin or you could be able to put nanoparticles in some kind of sandwiched layer between two inert components and embed that in the skin.   There are obviously lot of health and safety issues to go through here.

Interviewer - Chris Smith

Also, but not half as many as they are probably were for Botox in the first place.   Now, talking about developing new techniques, that's where animal experiments come in and Victoria, there's now news that there is a way to improve how we actually use animals in research so that we get more meaningful information out of it.

Interviewee - Victoria Gill

Possibly yeah!   And this comes for a recent experiment done by Julian Griffin and his group at the University of Cambridge and it's all about metabonomics, and this is looking at the metabolite profiles that sort of, rather than genomics, looking at metabonomics.   So profiling all little metabolites that are made from organisms that live in our gut.   What is grouped at was they took two different strains of rats, Kyoto and Wistar rats they are both often used for experiments for drugs testing particularly and they gave them a toxin called orotic acid, which is used to mimic the symptoms of fatty liver disease in humans and what they found was these two different strains of rats produced very different liver metabolites, when they're given this toxin, so you get two fundamentally different animal models of what's supposed to be a model of the same disease.

Interviewer - Chris Smith

And the key question is of course which one would apply to a human?

Interviewee - Victoria Gill

Yeah exactly!   So, one of the things that this group are saying that needs to be looked at closer now is how to bring these animal models closer to human profiles of these particular rare diseases.

Interviewer - Chris Smith

Have they got any clue as to how we can do that?

Interviewee - Victoria Gill

Well, they've already started doing that, particularly in China with mini-pigs, just selecting an animal that has a closer metabolic profile to a human.   So, these mini-pigs are just far closer to humans than any strain of rodent could be, but one of the other things that they can do is just by sort of sifting through the different strains of rodents, we can find which of the sort are more appropriate animal models, which provide a better and more accurate profile of a certain disease or which are more appropriate for testing a particular drug.

Interviewer - Chris Smith

That sounds very laudable, but what's the timing on being able to do this and have something that's meaningful and trustworthy?

Interviewee - Victoria Gill

It's a big ongoing process.   I mean, there are quite a few groups, there's a one group at Imperial College that are very much focussed on metabonomics and the study of metabonomics and believe strongly that this is the future of drug testing, this is where it's all going that we need to know the sort of genomic profiles of all of these organisms that live in our gut, that may call up these proteins that fundamentally change our responses to different drugs, in order that we can improve animal models and improve drugs testing fundamentally.

Interviewer - Chris Smith

So from guinea pigs to mini pigs it seems.   Thank you very much Victoria.   And now to the science of the very small.   Fraser Stoddart is working on ways to revolutionize microchips, but he has been rewarded with more than just a fast computer.   He's got a knighthood too.

Interviewee - Fraser Stoddart

I'm a chemist who believes and likes to create substances that are quite abstract and unnatural and in so doing put together compounds that contain mechanical bonds.   So, in addition to the normal chemical bonds there are mechanical bonds that are represented like a link in a chain or a ring on a dumbbell like an abacus.

Interviewer - Chris Smith

Have you always been encouraged to do this by the people, because initially some people would say, well that's all very well, its nice and pretty to look at, but what's its actual role? What's its function?

Interviewee - Fraser Stoddart

No I think in the beginning, there was a lot of scepticism as to what use the science, the research could be because the entities are novel and unique may be even exotic in some people's eyes, but the question was always asked for, good, what are they for?

Interviewer - Chris Smith

And can you do things with them now?

Interviewee - Fraser Stoddart

Yes, well we've been able to manufacture them in a way whereby they take up two different stakes, as a result   of stimulus and as such they make excellent switches, so these molecular switches which are no more than the smallest ones, one nanometre cube have been incorporated into devices and in particular memory devices and it transpires that.   This very week, coming up, there will be an article in the magazine Nature describing the fabrication of molecular memory at the density of 1011 bits per square centimetre which translated into simpler languages that these 160,000 bits are contained in the size of a white blood cell.

Interviewer - Chris Smith

Absolutely tiny, so when you are dealing with something that small and it's literally collections of clusters of atoms, how do you manipulate them and get them in the right place in the first place?

Interviewee - Fraser Stoddart

Well we used the technique that involves spreading the molecules right onto a water surface and they form a one-molecule thick layer on a trough which is then the setting from which a device is made by simply putting a chip into the trough and drawing it out and if you do this in a particular way, then you can transfer one molecule thick, a so called monolayer of molecules, to a surface and then having done that you can bring another surface or wire down on top and so you create a sandwich of molecules between two wires and this is called the crossbar and this crossbar can be in fact repeated over and over and then the one that's described in Nature involves 400 wires going in one direction and then at 90 degrees or orthogonal to these wires another 400 and these together give you the 160,000 crossover points.

Interviewer - Chris Smith

And how much better is that than existing technology -- the Pentium processor I've got sitting on my desk for example?

Interviewee - Fraser Stoddart

If you extrapolate to where the density is expected to be, with the silicon based technology, it's round about 15 years ahead of its time.

Interviewer - Chris Smith

Despite the fact that you work on very very small, you still managed get your self a big honour or may be even I should say two very big honours this year, haven't you?

Interviewee - Fraser Stoddart

That's right.   So I had the very big surprise of hearing that I was in the New Years Honours List as a Knight Bachelor just as the year 2006 came to an end and then earlier this week, there was further news I think on Tuesday from the capital Riyadh, in Saudi Arabia that I had won the 2007 King Faisal International Prize for Science and that was the second one, particularly welcomed because of the fact that I was the sole winner and that chemistry was picked out to have that happen in the week of getting a knighthood for services to chemistry and molecular nanotechnology, that has been particularly uplifting because for all my professional life, I've been very much someone who has loved doing my subject and loved pursuing chemistry.

Interviewer - Chris Smith

Fraser Stoddart or should be that be Sir. Fraser Stoddart.   He's at the University of California, Los Angeles.   And now to the sober subject of the US Death Penalty and it turns out that people are unhappy about the way criminals are being executed, Victoria.

Interviewee - Victoria Gill

Yeah! As of the start of 2007, nine US states have now stayed executions based on cases that have been brought by condemned prisoners who have questioned the constitutionality of lethal injection.   Based on the fact that there is an eighth amendment to the US constitution that states that cruel and unusual punishment is illegal.   And there have been a few cases of botched injections of not being able to find veins quickly enough to give IVs or of certain components of this drug protocol causing pain and now there have been a number of cases that have been brought by prisoners that have led to executions being stayed and this drug protocol being brought under the microscope to be reviewed.  

Interviewer - Chris Smith

So what's really the major complaint that the fact that people are experiencing traumatic execution?

Interviewee - Victoria Gill

There are a number of complaints.   One is that because the American Medical Association don't allow their members to be directly involved in executions, these executions cannot be properly medically controlled.   Another is that because this three drug protocol consists of a muscle relaxant and a general anaesthetic that's very fast acting, whilst the muscle relaxant is given, it might lead to the masking of what would be extreme pain during the administration of potassium chloride, which would just burn and sear through your veins as it travels to your heart.   So, there are a number of complaints and quite a lot of evidence from witnesses from botched injections over a number of years and this is the same protocol that's been used since 1977.   And one of the things, one of the issues of concern is that the selection of this three-drug protocol was really a policy decision, it was recommended by an anaesthesiologist called Jay Chapman in the '70s who said that it was an extremely humane way to cause to bring about death.   But since then, this same anaesthesiologist has said that he wouldn't actually recommend this, this triple drug protocol anymore.   He would say that it would be more humane if you can ever make that judgment to just give a very high dose of a barbiturate, even though this would take much longer, it would essentially just put a person to sleep, similar to the way that you euthanize an animal. 

Interviewer - Chris Smith

Thanks Victoria.   John Sheldon is a criminal defence attorney in the US who would also like to see things change.

Interviewee - John Sheldon

The problem with lethal injection is the people that administer the drugs have no medical training at all, so they don't know how to place an IV, they don't know how to mix and administer drugs and they don't know how to monitor an inmate when a problem occurred.   The second problem is with the drug scheme.   You use three drugs in lethal injection, sodium thiopental, that's the anaesthesia, pancuronium bromide that induces paralysis, and the third is potassium chloride and that is supposed to induce cardiac arrest.   The problem with the drug scheme is it would be a criminal act to euthanize an animal with pancuronium.   There has been a panel of veterinarian experts who got together in the year 2000, issued a report saying that, pancuronium should not be used euthanizing animals; its too high risk to cause a pain and suffering and unnecessary complication; yet they use pancuronium in executing people, whereas you couldn't use it to put your dog to sleep.

Interviewer - Chris Smith

But many people would say that it's all very well, having this moral approach to this, but the people that were convicted of these crimes didn't really have the same enthusiasm for the welfare of their victims.

Interviewee - John Sheldon

Right, that's something we hear a lot of and superficially that has some appeal, doesn't it?   Yet, so, the argument I suppose is that a little bit of torture is okay and when we're talking about torture, we're not talking about unnecessary pain.   When you execute somebody or euthanize an animal, there may be an amount of necessary pain and suffering that goes along with it, but we're talking about pain and suffering that's unnecessary linked to with this.   It's something that we know about and can easily stop because we don't do it to animals.   Now, in England, for example, you don't even execute people, let alone advocate torturing plus execution.   There really are only three countries that do substantial executions -- China, Iran, and the United States and none of those three countries would legally advocate the torture aspect that we are doing in the United States.

Interviewer - Chris Smith

But why has America decided to adopt lethal injection as the way or the means of choice of doing away with people? Why not, say, use hanging which we've seen in the case of Sadam Hussain recentl