Future In Our Hands

Just another WordPress.com weblog

Statins ‘may cut C-section risk’

Statins ‘may cut C-section risk’

Pills

Statins are now very widely used by the NHS

Taking cholesterol-lowering statins may help minimise the risk of an emergency Caesarean, researchers suspect.

Work by a University of Liverpool team suggests high cholesterol levels may weaken contractions enough during labour to rule out a natural delivery.

The study of 4,000 pregnancies found overweight women were far more likely to need an emergency Caesarean because of a slow labour.

Statins are already widely prescribed to cut the risk of heart disease.

If we can find a way to reduce the chances of a C-section in these women, that would be great
Mr Patrick O’Brien
University College Hospital London

The Liverpool team suggest that the drugs might be given to women in the final three months of pregnancy to reduce their cholesterol level – and potentially cut the risk of needing an unplanned Caesarean.

Laboratory tests on samples of muscle tissue taken from the uteruses of overweight women confirmed that its ability to contract was compromised.

Further analysis suggested that this might be due to reduced flow of calcium into the muscle cells.

The researchers believe high levels of cholesterol may be the problem, disrupting both cell membranes and key signalling pathways.

Natural mechanism

Mr Patrick O’Brien, a consultant obstetrician and gynaecologist from University College Hospital London, said the work was interesting.

“If we can find a way to reduce the chances of a C-section in these women, that would be great,” he said.

“Overweight women do have an increased risk of complications such as thrombosis and infection, so they would really benefit.”

However, Mr O’Brien said doctors had avoided recommending statins in pregnancy because a woman’s cholesterol level tends to rise naturally when she is pregnant, suggesting cholesterol may be needed by the developing foetus.

“We have avoided trying to counteract that in case it is somehow going against a natural physiological adaptation of pregnancy,” he said.

Mr O’Brien added that there were other reasons why overweight women were more likely to need an emergency Caesarean. For instance, they tend to have bigger babies.

Around 150,000 Caesareans are carried out in England and Wales each year.

Women who have Caesareans take longer to recover and have a higher risk of infection and bleeding, while babies are more likely to suffer breathing problems.

The operation is also far more costly to the NHS than a vaginal delivery.

June 18, 2008 Posted by | Uncategorized | Leave a comment

Low cholesterol ‘link’ to cancer ?

Low cholesterol ‘link’ to cancer

Generic heart attack photo

Statins can reduce the risk of having a heart attack

People who significantly cut their cholesterol levels with statins may raise the risk of cancer, a study says.The study of 40,000 people found those with little of the “bad” cholesterol LDL saw one more cancer case per 1,000 than those with higher levels.

The Boston-based researchers could not say if this was a side-effect of the statin or due to the low cholesterol.

They also write in the Journal of the American College of Cardiology that the benefits of statins outweigh the risks.

“The analysis doesn’t implicate the statin in increasing the risk of cancer,” says lead author Richard Karas of Tufts University School of Medicine in Boston. “The demonstrated benefits of statins in lowering the risk of heart disease remain clear.

“However certain aspects of lowering LDL with statins remain controversial and merit further research.”

Reservations

Researchers looked at the summary data from 13 trials of people taking statins – a total of 41,173 patients.

These findings do not change the message that the benefits of taking statins greatly outweigh any potential risks
British Heart Foundation

They examined the relationship between low, medium and high doses of statins and rates of newly diagnosed cancer.

Higher rates of the disease – which were not of any type or location – were observed in the group with the lower levels.

The authors noted their findings were particularly important at a time when more and more trials show significant reductions in LDL levels can greatly benefit cardiovascular health.

Cancer Research UK was wary of the study.

Cancer information officer Dr Alison Ross said: “The findings of this study should be treated with caution – it is based on summary data from previous trials and, as the authors point out themselves, it does not prove that low LDL cholesterol levels can increase cancer risk.

“Much more research is needed before any firm conclusions can be made.”

The British Heart Foundation said they had long known of a relationship between low cholesterol and cancer.

“While this highlights an association between low levels of LDL and cancer, this is not the same as saying that low LDL or statin use increases the risk of cancer,” said June Davison, cardiac nurse.

“There is overwhelming evidence that lowering LDL cholesterol through statins saves lives by preventing heart attacks and strokes. These findings do not change the message that the benefits of taking statins greatly outweigh any potential risks.”

June 18, 2008 Posted by | Uncategorized | Leave a comment

Cholesterol genes ‘protect heart’

Cholesterol genes ‘protect heart’

Cholesterol

Cholesterol appears to play a key role in heart disease

A third of the population have genes that could help them in the fight against heart disease, say scientists.

A study of 147,000 patients suggests that certain types of the CETP gene might increase the levels of so-called “good” cholesterol.

UK and Dutch research, published in the Journal of the American Heart Association, found a 5% cut in heart attacks for those with the key types.

A UK geneticist said it could point to drugs which help many more people.

What it does provide are important insights into the ’cause and effect’ relationship, and if you understand this better, you can develop drugs which target it
Dr Aroon Hingorani
University College London

Scientists already know that cutting the levels of “bad” cholesterol in the bloodstream protects your heart, and well-established drugs such as statins aim to do precisely this.

The relationship between the levels of “good”, or HDL, cholesterol, and heart health are less clear, although there is some evidence that raising these levels is good for you.

The team from Cambridge and Newcastle universities, and the University of Groningen in the Netherlands, merged the results of almost 100 other studies, involving 147,000 people worldwide.

They looked for the effect of having one of six different variations of the CETP gene.

The most popular three all seemed to carry a modest positive effect, raising HDL cholesterol levels by between 3% and 5%, and people with them were less likely to have a heart attack.

Cause and effect

Professor John Danesh, who led the study, said that the findings added weight to the idea that heart disease could be prevented by raising HDL levels, perhaps by drugs that blocked CETP.

A trial into a drug which raised HDL cholesterol by influencing CETP was abandoned in 2006 due to an increase in heart disease and deaths, but some scientists believe it may still be possible to target the gene effectively and safely.

Professor Peter Weissberg, of the British Heart Foundation, which funded the study, said: “Researchers are questioning whether approaches that raise HDL cholesterol could further prevent heart disease.

“This suggests that it may have benefits, but that more studies are needed to determine how much might be derived.”

Dr Aroon Hingorani, a lecturer in genetics from University College London, said that the relatively small decrease in risk meant that the presence of a particular variant of the CETP gene could not help predict with any accuracy the risk of an individual falling prey to heart disease.

She said: “What it does provide are important insights into the ’cause and effect’ relationship, and if you understand this better, you can develop drugs which target it.”

June 18, 2008 Posted by | Uncategorized | Leave a comment

no guarantee

Warning issued over egg freezing

Mother and baby

Many women are delaying trying for children

Egg freezing should not be offered to women who want to put off having a family purely for lifestyle reasons, say experts.The American Society for Reproductive Medicine (ASRM) warned the procedure was still experimental, and the chances of success poor.

It said it would be wrong to give women a false sense of hope. Instead they should be offered counselling.

However, a UK expert said egg freezing was a valid option for some women.

It is wrong to deprive women of this option, which many of them say is empowering
Dr Gillian Lockwood
Midland Fertility Services

An increasing number of women are choosing to freeze their eggs for social reasons in the hope they will be able to have a child when they are older.

Critics argue they are delaying motherhood for the wrong motives, such as climbing the career ladder or until they have more money.

Dr Marc Fritz, of the ASRM, said it would be wrong for women who have frozen their eggs to think they had ensured their future fertility.

He said: “Existing medical evidence simply does not justify that conclusion.”

The ASRM estimates that the overall live birth rate from frozen eggs is as low as 2% per egg.

It warned the figures may be even lower for women over 35 – the age at which fertility begins to decline rapidly.

Dr Fritz said a 25-year-old woman freezing her eggs now would have more chance of achieving a pregnancy through IVF using her fresh eggs when she was 35.

Successes

At the end of 2006, 185 women in the UK had eggs on ice. Many are cancer patients whose fertility is affected by treatment.

Four babies have been born from egg freezing in the UK – all following treatment at Midland Fertility Services.

Dr Gillian Lockwood, medical director, argued success rates using frozen eggs were comparable with those using frozen embryos.

She dissuades older women from freezing their eggs due to low success rates.

But she added: “As long as women know it’s not an insurance policy or a guarantee, then it remains an option they may wish to pursue.”

“Many of those women have been with commitment-phobic men or have not found Mr Right, or they are part of a couple that needs two salaries to get a mortgage.

“These are social issues but it is wrong to deprive women of this option, which many of them say is empowering.”

Caution key

Dr Simon Fishel, of the CARE Fertility Group in Nottingham, agreed it was important to explain to women that egg freezing was experimental, and carried no guarantee of success.

“Although significant research has been undertaken, and babies are being born from these new techniques, caution and counselling are imperative at this stage, and for several years to come.”

Josephine Quintavalle, of the campaign group Comment on Reproductive Ethics, said the ASRM had issued “sound advice”.

She said: “The best solution to lifestyle problems is to change one’s lifestyle.

“Have babies naturally at the time nature intended and give IVF a miss altogether.”

 

June 17, 2008 Posted by | Uncategorized | Leave a comment

equal opp

Egg-freezing technique ‘is safe’

Freezing eggs

Method allows women to delay motherhood

A method of storing human eggs which allows women to postpone motherhood is as safe as conventional IVF treatment, research suggests.

A Canadian study, published in the journal Reproductive Biomedicine Online, looked at 200 children conceived using “vitrified” eggs.

The technique involves rapid freezing, and could also help women whose fertility is threatened by cancer.

A UK expert said it was encouraging – but more research was needed.

Why shouldn’t women have the same opportunities as men?
Dr Allan Pacey
Fertility specialist

Although sperm and embryos are often frozen and successfully thawed, early ways of freezing eggs have proved far less successful.

The formation of ice crystals in the liquid within the egg can damage its structure, rendering it unusable.

“Vitrification” involves the removal of water from the egg, the addition of an “antifreeze” solution, then “flash freezing” in liquid nitrogen.

It is suggested that up to 95% of eggs survive the process, compared with 50% to 60% using older methods.

It is already available at a handful of clinics in the UK, costing up to £3,000, plus a small fee for annual storage.

Women have a fixed number of eggs to last them a lifetime, and fertility drops sharply from the late-30s onwards as the number of eggs dwindles.

Effective and safe egg-freezing methods would allow eggs to be harvested, then used to produce an IVF pregnancy later in life.

Aside from the wish to delay motherhood beyond their 30s and 40s, some women may use this technique for medical reasons, perhaps if they are facing cancer treatment which will render them infertile, or a premature menopause.

The researchers, from McGill university in Montreal found that the rate of birth defects among the 200 children conceived using vitrified eggs as 2.5%, roughly the same as in natural pregnancies and IVF.

Research call

Dr Allan Pacey, the secretary of the British Fertility Society (BFS), said that more, similar, studies would be needed before the safety of the procedure could be established.

“The British Fertility Society would say that this should only be offered in the UK as part of a controlled trial.

“We are getting close to the stage where I would be comfortable offering this to women who are about to have chemotherapy for cancer.”

He said that, although the BFS had no policy on using egg-freezing for “social” reasons, his personal view was that there were no ethical problems with offering women the chance to plan their families in this way.

“We have been offering men the chance to freeze their sperm for this reason for years now, and I don’t really see any great difference between the two.

“Why shouldn’t women have the same opportunities as men?”

June 17, 2008 Posted by | Uncategorized | Leave a comment

‘Hunger hormone’ depression link

‘Hunger hormone’ depression link

Woman holding her stomach

Ghrelin regulates hunger pangs

High levels of the “hunger hormone” ghrelin have an antidepressant effect, US researchers claim.

Blocking the body’s response to ghrelin has been suggested as a weight loss treatment but it may also produce unintended effects on mood, they said.

The Nature Neuroscience study found mice with increased levels of the hormone showed fewer signs of depression and anxiety.

Experts said the idea was interesting but further studies were needed.

Ghrelin is released by the empty stomach into the bloodstream before moving to the brain, where it triggers feelings of hunger.

An unfortunate side effect, however, is increased food intake and body weight
Dr Jeffrey Zigman

Treatment with the hormone itself – or a drug designed to cancel its effects – might be able to help both people who are eating too little, such as cancer patients, or those who eat too much, researchers believe.

In the latest study, Dr Jeffrey Zigman and colleagues restricted the food intake of laboratory mice for 10 days, causing their ghrelin levels to quadruple.

Compared with mice who had free access to food, the calorie-restricted mice showed lower levels of depression and anxiety when subjected to mazes and other behaviour tests.

Hormone response

The team also looked at mice genetically engineered to be unable to respond to ghrelin.

When they were fed a restricted-calorie diet they did not experience the antidepressant or anti-anxiety effects.

The researchers found the same thing when they induced higher ghrelin levels by subjecting the mice to stress.

Those mice that could not respond to ghrelin had greater levels of depression-like symptoms than the normal mice.

“Our findings in mice suggest that chronic stress causes ghrelin levels to go up, and that behaviours associated with depression and anxiety decrease when ghrelin levels rise,” said Dr Zigman, a researcher at UT Southwestern Medical Center in Dallas.

“An unfortunate side effect, however, is increased food intake and body weight,” he added.

He said the results made sense from an evolutionary standpoint, as hunter-gatherers may have had a survival advantage in remaining calm and collected in times of hunger in order for them to successfully find food.

The researchers are now hoping to look at the antidepressant effect of the hormone in conditions such as anorexia.

Professor Stephen Bloom, an expert in appetite regulation at Imperial College London, said it was reasonable to believe that ghrelin had an impact on behavioural responses other than just hunger.

But he said there was a lot of research to be done before it could be confirmed that a hormone released in the stomach can have an effect on mood in the brain.

“The role of ghrelin in the gut and in the brain are likely to be completely different,” he said.

June 16, 2008 Posted by | Uncategorized | Leave a comment

Hunger pangs ‘may trigger memory’

Hunger pangs ‘may trigger memory’

Hungry man

Hunger is controlled by a key hormone

New research suggests it may be wise to revise for and sit exams on an empty stomach as hunger can help with the creation and retrieval of memories.American scientists found the hunger hormone ghrelin can increase the number of nerve connections in the area of the brain where new memories are formed.

The study raises hopes of drugs to treat impaired learning and memory in diseases such as Alzheimer’s.

The Yale University study features in the journal Nature Neuroscience.

Memory can be switched on and off, and often it is switched on at times of stress
Professor Stephen Bloom

Ghrelin is released by the empty stomach into the bloodstream, and is known to activate receptors throughout the brain.

Scientists already knew that the hormone acts on an area of the brain called the hypothalamus to trigger feelings of hunger.

However, the hormone’s effect elsewhere in the brain has remained something of a mystery.

More connections

The Yale team has discovered that it seems to impact on the functioning of a second area known as the hippocampus, which is known to be essential to learning.

The researchers found mice bred to lack the ghrelin gene had 25% fewer ‘synaptic’ connections between nerve cells in this area.

They also showed that injecting normal mice with extra ghrelin increased the number of synapses in the hippocampus – and improved the animals’ performance in several learning and memory tests.

Writing in the journal, the researchers said: “The study provides evidence that ghrelin may control higher brain functions and may represent a molecular link between learning capabilities and energy metabolism.”

The researchers say it might be possible to use the hormone to develop new drugs to combat impaired learning and memory, but warn that weight gain could be a side effect.

Professor Stephen Bloom, an expert in appetite regulation at Imperial College London, told the BBC News website: “Memory can be switched on and off, and often it is switched on at times of stress.

“The paper is pretty interesting and it is entirely plausible that we are more alert and keyed up to both remember and recall more readily when stressed by hunger.

“If we weren’t our individual forbears might have died out in the competition for food.”

 

June 16, 2008 Posted by | Uncategorized | Leave a comment

amoebae invasion

Study cracks amoeba attack tactic

An amoeba in the colon

An amoeba is capable of evading the immune system for a long time

The tiny creature behind tens of thousands of dysentery deaths each year has a crafty method of slipping past our immune system, claim researchers.

US scientists say amoebae can get rid of giveaway chemicals on their surface.

The study in the journal Genes and Development suggests a similar technique helps malaria parasites get into human cells.

A UK specialist said amoebic dysentery, once diagnosed, is curable but the findings could aid vaccine development.

In theory, this idea could help people who are trying to work on a vaccine
Dr Graham Clark
London School of Hygiene and Tropical Medicine

It is suspected that the number of people infected by amoebae amounts to millions worldwide.

Most of them will never suffer bloody diarrhoea, which is the first sign of amoebic dysentery, an infection which kills approximately 70,000 people each year.

In most symptomless cases, the body’s immune system eventually gets rid of the infection, but it can persist for years on end.

Researchers from Johns Hopkins and Stanford universities in the US believe they have found out why the single-celled organism is capable of evading the immune system for so long.

Existing research on the plasmodium malaria parasite revealed that it used a type of cell chemical called a “rhomboid enzyme” to help it get into the host cell.

A scan of the DNA of other parasites revealed the same chemical in amoebae, and led to the discovery this chemical was capable of getting rid of a protein called lectin found on its surface.

Surface security

Normally the immune system works out the difference between friend and foe by looking for “foreign” surface proteins and, by cutting them loose, the amoeba is able to stay undisturbed.

Dr Sin Urban, who led the study, said: “This is the first enzyme to be identified which looks like it could mediate immune system evasion.”

Now the hunt could be on for drugs which specifically target the rhomboid enzyme.

Dr Graham Clark from the London School of Hygiene and Tropical Medicine, said that while effective treatments for amoebic dysentery did exist, it was often hard to identify, and could be mixed up with bacterial infection or even Crohns disease.

“In theory, this idea could help people who are trying to work on a vaccine.

“But if you understood how these proteins are being ‘sloughed off’, that could help you get around this process.”

June 15, 2008 Posted by | Uncategorized | Leave a comment

‘Darkest ever’ material created

‘Darkest ever’ material created

By Helen Briggs
BBC News science reporter

Carbon nanotubes (Image courtesy of Institute of Nanotechnology)

Carbon nanotubes are a basic building block of nanotechnology

The “darkest ever” substance known to science has been made in a US laboratory.

The material was created from carbon nanotubes – sheets of carbon just one atom thick rolled up into cylinders.

Researchers say it is the closest thing yet to the ideal black material, which absorbs light perfectly at all angles and over all wavelengths.

The discovery is expected to have applications in the fields of electronics and solar energy.

Theoretical clues

An ideal black object absorbs all the colours of light and reflects none of them. In theory, it should be possible to make something that approaches the “perfect absorber”.

They’ve made the blackest material known to science
Prof Sir John Pendry

But it has proved difficult to construct an object that does not reflect light at all.

Researchers at Rensselaer Polytechnic Institute in Troy, New York, turned to carbon nanotubes – structures made from carbon, billionths of a metre across, that have unique properties.

Theory suggests that nanotubes might make a super black object, and experts are just starting to test these predictions.

A team led by Dr Pulickel Ajayan, who is presently at Rice University in Houston, Texas, built an array of vertically aligned, low-density carbon nanotubes. Dr Shawn Lin measured the optical properties.

The roughness of the material’s surface was tuned to minimise its optical reflectance.

BUCKYBALLS AND NANOTUBES
PA/BBC
Closed cages of carbon atoms
Appear as spheres and tubes
Electrical properties tuneable
Could form tiny circuit wires
Tubes make strong materials
Buckyballs will block HIV virus

Experiments showed that this “forest” of carbon nanotubes was very good at absorbing light, and very poor at reflecting it.

Reporting their findings in the journal Nano Letters, Dr Ajayan, Dr Lin and colleagues say the reflectance of the material is three times lower than previously achieved.

This makes it the “darkest man-made material ever”.

“The periodic nanotube structures make an ideal candidate for creating superdark materials, because it allows one to tailor light absorption by controlling the dimensions and periodicities of nanotubes in the structure,” said Dr Ajayan.

Commenting on the study, Professor Sir John Pendry, who first predicted that such a discovery might be possible, said the results were promising.

“They’ve made the blackest material known to science,” the theoretical physicist from Imperial College, London, told BBC News.

“The application will be to things like more efficient solar cells, more efficient solar panels and any application where you need to harvest light,” he added.

SOME POTENTIAL USES OF NANOTECHNOLOGIES
Nanotechnology in our lives
1 – Organic Light Emitting Diodes (OLEDs) for displays
2 – Photovoltaic film that converts light into electricity
3 – Scratch-proof coated windows that clean themselves with UV
4 – Fabrics coated to resist stains and control temperature
5 – Intelligent clothing measures pulse and respiration
6 – Bucky-tubeframe is light but very strong
7 – Hip-joint made from biocompatible materials
8 – Nano-particle paint to prevent corrosion
9 – Thermo-chromic glass to regulate light
10 – Magnetic layers for compact data memory
11 – Carbon nanotube fuel cells to power electronics and vehicles
12 – Nano-engineered cochlear implant

June 15, 2008 Posted by | Uncategorized | Leave a comment

soundproofs houses, submarines etc

Experts unveil ‘cloak of silence’

Orchestra

A working device could be used to enhance the acoustics of concert halls

Being woken in the dead of night by noisy neighbours blasting out music could soon be a thing of the past.

Scientists have shown off the blueprint for an “acoustic cloak”, which could make objects impervious to sound waves.

The technology, outlined in the New Journal of Physics, could be used to build sound-proof homes, advanced concert halls or stealth warships.

Scientists have previously demonstrated devices that cloak objects from microwaves, making them “invisible”.

“The mathematics behind cloaking has been known for several years,” said Professor John Pendry of Imperial College London, UK, an expert in cloaking.

“What hasn’t been available for sound is the sort of materials you need to build a cloak out of.”

Sound shield

The Spanish team who conducted the new work believe the key to a practical device are so-called “sonic crystals”.

These artificial composites – also known as “meta-materials” – can be engineered to produce specific acoustical effects.

Acoustic cloak simulation

Sound waves are channelled around an object by sonic crystals

“Unlike ordinary materials, their acoustic properties are determined by their internal structure,” explained Professor Pendry.

These would be used to channel any sound around an object, like water flowing around a rock in a stream.

“The idea of acoustic cloaking is to deviate the sounds waves around the object that has to be cloaked,” said Jose Sanchez-Dehesa of the Polytechnic University of Valencia, one of the researchers behind the new work.

He believes a material that consists of arrays of tiny cylinders would achieve this effect.

Simulations showed that 200 layers of this metamaterial could effectively shield an object from noise.

Thinner stacks would shield an object from certain frequencies.

“The thickness depends on the wavelength you want to screen,” he told BBC News.

Sub systems

Dr Sanchez-Dehesa now wants to make and test such a material in the lab to confirm the simulations.

But researchers, such as Professor Pendry, believe the initial work is already an important first step.

Woman with finger on lips

Acoustic cloaks could be used to make soundproof rooms or buildings

“It’s not an unrealistic blueprint – it doesn’t demand that we do extraordinary things,” he said. “This is something that can easily be manufactured.”

If a material could be commercialised, both researchers believe it could have many applications.

Walls of the material could be built to soundproof houses or it could be used in concert halls to enhance acoustics or direct noise away from certain areas.

The military may also be interested, the researchers believe, to conceal submarines from detection by sonar or to create a new class of stealth ships.

However, the material may need to be optimised first.

“You don’t want to wrap a submarine in something that is heavy and several inches thick,” said Professor Pendry. “It would add quite a lot to the Navy’s fuel bill, I think.”

Light touch

The research builds on work by scientists from Duke University in North Carolina, US, and the Hong Kong University of Science and Technology.

Duke University

Duke University researchers created an invisibility cloak in 2006

Earlier this year, independent teams from the two institutions demonstrated the mathematics necessary to create an acoustic cloak.

Other scientists have shown that objects can be cloaked from electromagnetic radiation, such as microwaves.

For example, in 2006, scientists at Duke University showed how a small copper cylinder could be rendered invisible from microwaves.

The technique used a metamaterial consisting of 10 fibreglass rings covered with copper elements, to deflect the microwaves around the object and restore them on the other side.

To an observer it looked like the microwaves had passed straight through the cylinder.

Other researchers hope to build the holy grail of cloaking: an invisibility device that would channel light at wavelengths normally visible to the eye.

However, this technology is in a more primitive state, according to Dr Sanchez-Dehesa.

“We believe the acoustic cloak is more feasible than a similar device for light,” he said.

June 15, 2008 Posted by | Uncategorized | Leave a comment