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Red Meat & Heart Disease, Measles, Hypopituitarism

What's the story behind the reported links between red meat and heart disease? Plus a measles outbreak in Swansea, and why head injury can lead to unrecognised pituitary damage.

What's the story behind the headlines about the links between red meat and heart disease? Researchers have reported that the way meat eaters' gut bacteria process a substance in red meat, carnitine, could be the trigger for heart disease. As the numbers of measles cases in Swansea rise, where else might be at risk of an outbreak and as the age of vaccination in Swansea has been lowered to 6 months, why do we vaccinate babies and young children when we do? Around a million people in the UK every year have some form of head injury. Most make a full recovery but there is growing concern that doctors are missing a common complication of head injury. Dr Mark Porter investigates a condition called post traumatic hypopituitarism - the result of a damaged pituitary gland- a small vulnerable structure which sits at the base of the brain. It regulates the actions of hormones controlling everything from immunity and the thyroid gland, to normal growth, sex drive and fertility.

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28 minutes

Programme Transcript - Inside Health

Downloaded from www.bbc.co.uk/radio4

THE ATTACHED TRANSCRIPT WAS TYPED FROM A RECORDING AND NOT COPIED FROM AN ORIGINAL SCRIPT.  BECAUSE OF THE RISK OF MISHEARING AND THE DIFFICULTY IN SOME CASES OF IDENTIFYING INDIVIDUAL SPEAKERS, THE BBC CANNOT VOUCH FOR ITS COMPLETE ACCURACY.

 

 

INSIDE HEALTH

 

TX:  09.04.13  2100-2130

 

PRESENTER:  MARK PORTER

 

PRODUCER:  PAMELA RUTHERFORD

 

 

Porter

In today's programme, red meat hits the news but does the latest scare stand up to scrutiny?  Concussion - if you or a member of you family have ever been knocked out then you could be at risk of an easily missed complication of a knock on the head that can influence everything from your blood pressure to your sex life and it's common:

 

Clip

It's very difficult to estimate how many people live with post-traumatic hypopituitarism some studies suggest a million people, some studies suggest probably half a million but still we're talking about very, very large numbers of people that are not recognised or treated.

 

Porter

And measles - the outbreak in Swansea has been a stark reminder that the virus still poses a significant threat.  I will be getting an update on the latest developments in South Wales and asking if we are likely to see similar outbreaks across the UK, and whether it is just children and young adults that are at risk.

 

But first we go behind this week's headlines linking red meat to an early heart attack. Have researchers from America really found the missing link that explains why meat eaters are more likely to develop heart disease than their vegetarian peers? And should meat eaters be concerned? Catherine Collins is the principal dietician at St George's Hospital NHS Trust in London.

 

Catherine - before we look at the nature of the link - is it clear that meat eaters do actually suffer more heart disease?

Collins

We've always assumed that red meat is a major cause of heart diseases but actually the Epic study, which has looked at over half a million people in the UK and Europe, has shown that only those that are taking the largest amounts, over 160 grams a day or six ounce steak a day, are at much higher risk.  For the rest of us having red meat once or twice a week is actually quite useful because it gives us iron, which helps prevent against anaemia and that preventing against anaemia allows us to exercise more and do those lifestyle things which we're meant to do along with a healthy diet in preventing heart disease.

 

Porter

So why has there been so much excitement about this study?

 

Collins

Well I think people are excited because when we're looking at the risk of heart disease we only have a certain number of markers that we can use to actually try and predict our risk of heart disease - so we can look at cholesterol, we can look at blood pressure, we can look at your blood sugar level or your obesity level - and we can make a prediction as to are you likely to develop heart disease in the future.  Now the big problem is of course is that some people actually develop heart disease without those factors being altered and so what these researchers were trying to work on a hypothesis that there's a substance present in the blood and that this particular stuff when it gets into the bloodstream actually helps to speed up the hardening of the arteries and this would be a very new factor to add to the armoury we've already got of using blood cholesterol and blood pressure and so on in order to try and identify people at risk of heart disease.

 

Porter

Explain to me then the link between eating meat and the levels of this chemical in the blood.

 

Collins

The key issue is that the authors make the assumption that red meat causes heart diseases, even if it's very lean, it's very low in saturated fat and total fat.  Now that in itself is open to debate but if we work on the principle that perhaps there is a link between red meat and heart disease they were looking at a substance called carnitine which is found naturally in red meat.  It's a substance that's there as part of the meat's structure and we know that we can absorb it into our bloodstream and it's quite harmless in our bloodstream and does useful things in terms of fat metabolism.  But what these researchers were looking at was what happens to carnitine depending on whether you're a regular meat eater or you're a vegetarian and what they showed in a quite elegant set of experiments is that if you're a vegetarian that can be persuaded to take some meat and some carnitine supplements that your blood carnitine level rose because you've just eaten some carnitine but actually that's all that happened.  If you were a meat eater and you had the meat and the carnitine supplements you did absorb some of the carnitine but also you absorbed a substance which had been altered by your digestive bacteria into a more toxic substance and this is called TMA oxide - unfortunately we can't get away from the dodgy name.  But TMA oxide was thought to be a substance which independently irritates the blood vessel walls and accelerates the speed at which they're likely to fur up.

 

Porter

So the implications for those of us who are meat eaters are what?  I mean what sort of levels of meat intake were they talking about?

 

Collins

Well I think this is a really important aspect because if there was a new bio-marker, a new way of easily assessing heart disease risk that went beyond the traditional markers we have at the moment, it would be a very exciting development.  But when you look at the study that they did they actually gave people a sort of eight ounce rump steak and a carnitine supplement as well, so it meant that the people were taking in over 400 milligrams of carnitine a day in this single dose.  So what they were doing in both the vegetarian subjects and the meat eaters was giving them a massive plate of steak equivalent, if you like, and of course not many people would sit down and eat a steak that weighs over a pound in weight and if they did it probably wouldn't be that often in their diet.

 

Porter

So we don't quite know at the moment how relevant this might be to your average meat eater but does it make any difference how you eat that meat - I mean if I'm eating that meat with salad for instance does it make any difference to how it's metabolised?

 

Collins

Well this again is a really key point because of course when you're testing foods you're testing individual foods but we don't eat food, we eat diets - we eat a mixed diet.  So of course for people eating steak normally it might be steak and chips and peas and tomato, it could be a stir fried beef with beansprouts and noodles or whatever and in fact we know that the way in which foods interact together in a meal have a major impact on how that meal is digested.  So even if your gut bacteria want to play kiss chase, if you like, with your meat carnitine and try and convert it into this rather unpleasant substance the chances of it happening in a mixed diet is probably much, much reduced.

 

Porter

There might not be many people who are eating more than a pound of steak a day but there are lots of people taking carnitine substance, Catherine, as I'm sure you're aware.  We've had an e-mail here from Emma.  She says that she's healthy, exercises six times a week and takes carnitine supplements because she's been told by her gym that they will help her metabolise fat.  Of course there are lots of people out there who take carnitine supplements in muscle preparations to help them build muscles as well.  Should these people be worried do you think?

 

Collins

Well I certainly wouldn't recommend carnitine supplements especially in conjunction with a high protein diet that's based on meat.  But from this evidence if there is a link and certainly at high levels of carnitine intake they could show that this particular substance increased in the bloodstream and they've shown from mouse models that high TMA levels are associated with an accelerated damage in the artery wall from having this high level of carnitine.  So there really is no reason why you should take supplements.  This unfortunately for dieticians is exactly what happens in gyms and other nutritionistas - people with an interest in nutrition, understand a little bit of the science but don't quite know how it all fits together.

 

Porter

And what message should the rest of us take away from this research - people who have a moderate amount of red meat a week?

 

Collins

I would take away that actually we carry on doing what we've always done.  There's a number of flaws with the extended comments made by the researchers.  The big problem comes in trying to translate that into what should the public do and that's when we really do disagree because this particular substance in the bloodstream which they have associated with an increased risk perhaps of heart disease, this TMA oxide, occurs naturally when we eat oily fish or any other sea fish and it's also present in other foods like bread and asparagus and ice cream and chicken breast and so on and in fact we know that if you're eating a diet that's rich in seafood or rich in vegetables that's actually protective against heart disease.  So whereas I would suggest that actually large meat eaters and people taking these supplements should really think again about their diet, for the rest of us that have red meat a couple of times a week, add in fish, have plenty of vegetables, little bit of chicken and a little bit of what you fancy, we don't need to change what we're doing, just carry on as you are at the moment.

 

Porter

Catherine Collins thank you very much.  And you will find a link to the carnitine study, published in Nature Medicine, on the Inside Health website at bbc.co.uk/radio4.

 

From red meat to red rashes - measles has had more than its fair share of headlines over the last fortnight following the outbreak in Swansea. Parents are being urged to make sure their children have had the measles, mumps and rubella jab but the demand in Swansea has overwhelmed GPs so special drop in clinics have been set up to help out. Inside Health reporter Becky Leech visited one over the weekend at Morriston Hospital in the outskirts of the city.

 

Clinic actuality

 

Hayes

I'm Sara Hayes, I'm director of public health for Abertawe  Bro Morgannwg University Health Board.  We know that we've got cases of measles increasing, we know that although GPs are vaccinating very fast it's not fast enough to stop the outbreak so we want to catch anybody who needs an MMR today.  In my wildest dreams I didn't expect so many people, I'm thrilled at the response we've had I really am.

 

Lisa

My name is Lisa, I've got two children, one already in school who's been immunised and one who's turning three next month and isn't due to be immunised until August, so I've brought him to have his immunisations early.

 

Mother

Zac is nearly 12 and Kieran is 13.  They had their first MMR but with all the talk of autism and such I didn't allow them to have the second one but with this measles outbreak now I thought it was worth getting them done with the drop in clinic and a few of my friends know people who've had measles so it's a bit close for comfort then isn't it.

 

Sarah

My name's Sarah and I'm here with my middle daughter Lorraine, she's 12.  We paid, it was paid privately when the MMR came out because of the concern with the autism, for her to go and have the separate injections but this week we had a phone call from my doctor's surgery saying that they didn't think she'd be - was covered fully so they couldn't find any trace of the second lot so they advised us to come today for 10 to the open surgery to have the second lot done so she's covered at least.

 

Are you nervous?

 

Lorraine

No.

 

Sarah

No, no she's ready, just go in and get out, doesn't want the others to see her having it done though.

 

Porter

Well for an update on the latest situation in Swansea I am joined now by the Director of the Communicable Disease Surveillance Centre in Wales Dr Roland Salmon who is in our Cardiff studio.

 

Dr Salmon how many confirmed cases have there been now?

 

Salmon

As of lunchtime today we have 620 cases compared with 588 on Friday last week.  But we're still getting a number coming in, bearing in mind that this is reflecting the immunisation situation as it was a fortnight ago which is broadly before the recent big push.

 

Porter

Has anyone sort of estimated where this might top out at, what sort of level do you think we'll get to - are we going to reach the thousand?

 

Salmon

Well I think it's certainly perfectly possible.  Depending on the age group you're looking at you've got 10-15% of the population susceptible.  Now we're busy with our vaccination clinics clawing into that number but as you'll appreciate it takes a little bit of time for immunisation to take effect.

 

Porter

Roland, how serious have some of the cases been?

 

Salmon

Well measles is a serious disease and our experience has reflected this.  We've had in an excess of 50 people admitted to hospital, I know by last week, and I'm sure there will have been some more since then.

 

Porter

And some of these children are quite poorly presumably?

 

Salmon

Yes there are, I mean we quote something like one in five will get pneumonia, one in every thousand can get encephalitis and all these kinds of complications are being seen by the children's doctors looking after them.

 

Porter

You must be pleased by the response to the call to get vulnerable children protected - I suppose it's just a shame it takes an outbreak to achieve it?

 

Salmon

I mean I think it's true that in a sense you can't get people to tackle a problem till they see they've got a problem.  We're very encouraged by the numbers of people that have come forward and indeed I think one of the lasting legacies of this outbreak might be these images of people queuing to get their MMR vaccination, which will help to restore confidence for generations to come, so that people will be coming forward at 13 months and at just over three to get their two vaccinations on time in future.  Obviously that's the best protection that the population can have.

 

Porter

Dr Roland Salmon, thank you very much. The Director of Immunisation at the Department of Health is Professor David Salisbury and he joins me down the line from Richmond House in London.

 

Professor Salisbury, we've had an e-mail from listener Judy Adams who wants to know if there are any plans to offer MMR to older adults.  Presumably this might be of concern to anyone who's too old to have been offered vaccination as a child but is unsure as to whether they've actually had measles, so should they be worried?

 

Salisbury

Well MMR was introduced in 1988 and before that you really had an extraordinarily high chance of either having been vaccinated against measles or caught measles or been vaccinated against rubella, if you were a female, or caught rubella and almost everybody had caught mumps.  So we really don't worry too much about the people from before 1988 in regards to MMR.  If you're older and certainly beyond 30, 40 years of age you've almost certainly had measles and you shouldn't worry.

 

Porter

What about the age at which we give the MMR, I mean routinely the first dose is given around 12 months of age but in Wales they've reduced that to younger babies, what's the rationale behind waiting until a year or so?

 

Salisbury

Well the reason that we wait till a year, 12, 13 months of age, is to try to get this sort of optimum point when the mother's antibodies that have crossed to the baby during pregnancy have fallen such that they don't interfere with the vaccine and before babies really start to mix with others and increase the risk of actually catching measles.  So there is this sort of sweet spot at around 12 to 13 months of age when the vaccine works very well and the risk of exposure is still pretty small.  Now that balance changes when you find yourself in a circumstance as we're hearing from South Wales where they've got a lot of measles about.  If there's a lot of measles you really do need to protect younger children because some of the long term complications from measles can be catastrophic if caught by an under one child.  So for that reason we drop the age for the first dose, we count it as a sort of zero dose because we think it will be beneficial but it's not going to be as good as giving it at the age of a year and then when the child gets to a year we start again with the routine numbers of doses.  And measles is not a pleasant disease and if anyone listening knows that their child either had no doses of MMR or only one then they need to do something about it and get their child vaccinated.

 

Porter

When we're talking about children and young adults who may not be fully protected have you any - do you have a number in your head, what's the best guestimate of how many people might be vulnerable?

 

Salisbury

Well again it's difficult because it requires analysis of all of the historic data plus some people got vaccinated with single vaccines which - for which the data was not well recorded because they went to private clinics.  But we are talking in millions, we're not talking small numbers here.  Spread across the whole country these are considerable numbers.

 

Porter

Professor David Salisbury, thank you very much.

 

Inside Health's Margaret McCartney is in our Glasgow studio.  Margaret, are there any other parts of the UK that are particularly vulnerable?

 

McCartney

Yes I think is the answer.  There's publicly available information on this which will tell you what your region has in terms of coverage at the moment and I have to say we're not doing very well.  In England the total percentage of children who've had their booster - so two doses of MMR by the age of five years - are 88.1%, in Wales 89.9% and in the UK overall we've got 88.6%.  So we really are looking at a deficit here, not enough children are being immunised.

 

Porter

Because the magic figure is what?

 

McCartney

The World Health Organisation say that in order to prevent outbreaks and to have that magic herd immunity you want 95% coverage.

 

Porter

And that 95% that works on the theory that if some people slip through the vaccination, some of the older people like our listener Judy may not have met measles, they'll be protected anyway because there's no measles circulating in the community.

 

McCartney

That's right.  So the idea is that you've got enough people who've got immunity which is a good immunity within the community that you're not going to get rapid transmission of measles because this is a highly infectious disease.

 

Porter

But the figures are on an upward trend, they're not perfect yet but they're getting better aren't they?

 

McCartney

They are getting better but I think what really strikes me is the variation across the UK.  So up in Scotland we do not too badly - we've got 93% of our children aged five have had two MMR vaccinations.  But you compare it to London it's 80.8%.

 

Porter

That's significant because London's also a huge city and if you have a big outbreak in somewhere like Swansea imagine if it was to get into London, which must be potentially at risk?

 

McCartney

Well absolutely and that's the lowest coverage that we've got in the UK just now.

 

Porter

And I think another thing that we've learnt from this outbreak in Swansea is that measles can be a serious condition.

 

McCartney

Absolutely, it's one of the most serious yet preventable diseases that we have.  The World Health Organisation say that everyday globally 430 children die of what is a vaccine preventable disease.  And it wasn't very long ago in Dublin in the year 2000 where vaccine coverage was 79% and that's just one per cent off London just now, there were 111 children admitted to hospital, 13 ended up in intensive care, seven needed ventilated and there were three deaths.

 

Porter

And that was out of a total of something like 1500 cases wasn't it, so that's a significant death rate, very worrying.

 

McCartney

Absolutely and it's preventable, that's the big thing, this is a preventable disease so there's no need for any panic, all there is - is a need for I think us just to know that you can get your MMR vaccine for free on the NHS from your friendly local GP's surgery.

 

Porter

Margaret McCartney, thank you very much.

 

And there is a link to the latest coverage rates mentioned by Margaret on our website - go to bbc.co.uk/health and click on I for Inside Health.

 

Around a million people in the UK attend accident and emergency departments every year with some form of head injury. Most make a full and complete recovery - at least they appear to. But there is growing concern that doctors are missing a common complication of head injury that may not become apparent for months after discharge.

 

Post-traumatic hypopituitarism is the result of a damaged pituitary gland - a small vulnerable structure, and one that is critical for our wellbeing.  It sits at the base of the brain where it regulates the actions of eight different hormones controlling everything from immunity and the thyroid gland, to normal growth, sex drive and fertility.

 

It is the conductor of the hormone orchestra - ensuring the right amount of the right hormones are released at the right time and without it chaos ensues.

 

Jackie Flavell's son Luke was seriously injured in a road traffic accident last year.

 

Flavell

He'd had a severe injury to the head, he'd got four bleeds on the brain, you'd cracked the back of your head in four places and the front of his head.

 

Porter

And what did they tell you then about his injuries?

 

Flavell

That they were very severe, that the 48 hours were crucial and that they didn't think he'd make it.  They removed parts of Luke's skull to release the pressure and then they said that they thought he'd got a fighting chance.  We went from there didn't we?  And we had four and a half weeks in critical care, we spent six weeks in rehab and Luke was talking - basic words but he was communicating - he could stick his thumb up, he could engage with you - if you walked in the room and said hello he'd look at you.  And then the 9th October he completely changed.

 

Porter

Luke's recovery had stalled thanks to his pituitary gland - but you don't need to have been as seriously injured as Luke to damage it. Tony Belli is Reader in Neuro Trauma at Queen Elizabeth Hospital in Birmingham.

 

Belli

The pituitary gland is a very small gland that sits at the base of a skull, it's the size of a walnut, it's actually a very small gland and effectively it dangles from the brain, you can say, because it's attached to the brain by a very slender stalk but it's actually anatomically perhaps not very cleverly designed because it sits in a bony pouch and it's in a fixed position whereas the brain can actually move to some degree, particularly in the acceleration/deceleration injuries that are quite typical in road traffic accidents for example.  So the pituitary gland is fixed while the brain moves above it and that can damage the stalk, it can damage the vessel.

 

Porter

So if the brain - if the rest of the brain's moving and the pituitary stays where it is I mean that's where the damage happens?

 

Belli

That's where the damage happens, that could be one of the mechanisms because the pituitary gland is supplied by some very thin vessels round up that stalk and the vessels can be damaged in this kind of injury.

 

Porter

What are the consequences of a damaged pituitary, how would you notice as an individual?

 

Belli

People would notice lethargy, for example, feeling tired, feeling fatigue; muscle weakness, people sometimes notice actually losing the muscle ball for example; loss of libido; infertility and erectile dysfunction are common problems and heat or cold intolerance - those are the common complaints - in women periods can stop.  So it's very small but it controls a wide range of processes in the body.

 

Porter

And when it's damaged after a head injury is it an all or nothing - I mean does the pituitary either work normally or not at all?

 

Belli

No that's part of the problem, it could be one or more hormones are damaged and the damage can be very subtle.  So it could be, for example, the hormone is just mildly damaged and that may go unnoticed for a long time or the damage is only temporarily but it then obviously goes all the way to sort of full pituitary damage where the entire pituitary gland fails.

 

Porter

Which is exactly what happened to Luke Flavell a few months after his accident.

 

Flavell

I remember it as clear as anything - I walked in the room, said hello Luke and he just - there was just nothing, there was just nothing, he was vacant.  And we couldn't get any response from him and it was really, really hard watching your son change so much when he'd come so far.

 

Porter

What did he look like?

 

Flavell

He looked Botoxed.  And one of the nurses said he looks like a waxwork, his face had completely changed and he did look like a waxwork.  And we went to clinic and we saw Tony Belli, he walked in the room, took one look at Luke and said his pituitary gland's not working properly.  And then they did blood tests and it wasn't working and that was the reason. And on the 27th October Luke had a seizure and we then spent six hours with doctors trying to save his life again.  And it was horrendous, absolutely horrendous.  It's the most frightening thing I think as a family we've ever been through.  And then we spent 10 days on critical care and fortunately for us you pulled through.  We moved to the rehab and you took off and you're doing amazing, absolutely amazing, I'm so - so proud of you, so proud of you.

 

Porter

You've had quite a battle Luke haven't you.

 

Luke

It's one of them things.

 

Flavell

Mr Modest.

 

Belli

The immediate association is between severe head injury and pituitary damage and it's difficult to estimate the numbers but we think probably about a quarter of all severe head injuries but some people even say half of all severe head injuries have some form of pituitary damage and maybe it's a question of the harder you look the more you find.  But there are some studies suggesting even mild head injuries get pituitary damage and possibly with similar rates to those seen in severe head injuries.

 

Porter

And when you're talking a mild head injury and a severe head injury I mean how do you grade those?

 

Belli

A mild injury would be someone who's lost consciousness for a matter of seconds or a couple of minutes but mild also includes people that had an episode of feeling dazed or confused following a trivial knock on the head and this typically would be sports injury, for example, rugby or football and these are relatively common.

 

Porter

And they may never have seen a doctor about it.

 

Belli

Some people never actually go to see their doctor and this is one part of the difficulty in getting the right statistics for head injury.

 

Porter

What's your best estimate of the number of head injuries - significant head injuries - that we'd be having in the UK every year?

 

Belli

If you refer to these severe head injuries probably about 10,000 severe injuries admitted to intensive care for example but if you look at all the definitions of head injuries, including the mild head injuries, probably talking about close to a million people in the UK every year.

 

Porter

So even if a small percentage of those, less than the studies suggest, are having problems with their pituitary we're talking tens of thousands and possibly hundreds of thousands of people who are out there with a problem, most of them undiagnosed.

 

Belli

Most of them undiagnosed and in fact these are people that have survived initial injuries, so they have these persistent life type problems, it's very difficult to estimate how many people live with post-traumatic hypopituitarism, some studies suggest a million people, some studies suggest probably half a million but still we're talking about very, very large numbers of people that are not recognise or treated.

 

Porter

I can imagine there'd be quite a few people listening who may well have had a head injury in the past, they're suffering from the symptoms you talk about, which are quite vague - so sexual dysfunction, erectile dysfunction in men, weakness, fatigue etc. - if they wanted to pursue this to find out whether it was their pituitary I mean practically how do you test for it?

 

Belli

The first thing one could do is to go to their GP, for example, for a routine blood test.  The blood test has to be done, for example, at nine o'clock in the morning because some of the hormones fluctuate throughout the day, also if the hormones are low you can't necessarily assume that the gland is not functioning.

 

Porter

But if they're normal it would be reassuring?

 

Belli

If they're normal they could be reassuring.  There's a slight question even there that if you had a traumatic brain injury very recently your pituitary gland may actually fail a bit later, so say six months or a year later, two years later, so if you develop new problems there is an argument for perhaps going back to your GP for further tests.

 

Porter

Which begs the question - if we know about the condition we can treat it and we know that it's possibly quite common and can have a significant impact in life why aren't we looking for it routinely?

 

Belli

That is a very good question because my personal view is that we should look for it and certainly I have written articles and advocated this quite strongly, we should be looking for it.

 

Porter

And when you treat people who've got this problem how quickly do they respond and how well do they respond?

 

Belli

They respond very quickly and you see transforming effects on their quality of life, sometimes very, very soon.  Some of the hormones may take a couple of weeks to rise in the bloodstream but the effects can be very profound and very rapid.

 

Porter

Tony Belli - and you will find some useful links on post-traumatic hypopituitarism on the Inside Health page at bbc.co.uk/radio4.

 

Just time to tell you about the next Inside Health when we will be looking at tooth whitening and learning more the radio presenter's equivalent of collagen injections for wrinkles - what better way to take years off the way you sound, than a so-called voice lift. Join me next week to find out more.

 

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