Pill-sized scanner images gullet

Doctors have made a pill-sized device that can take detailed microscopic images of inside the gullet.

It is hoped the US technology could become an easier way of screening people for a condition called Barrett's oesophagus, which can lead to cancer.

Unlike current imaging techniques, the device can be used while the patient is conscious and takes only a few minutes.

The device has been tested in a small number of patients so far, Nature Medicine reports.

Although researchers at Wellman Center for Photomedicine at Massachusetts General Hospital in Boston say the device has potentially wide application, it could be particularly useful for Barrett's oesophagus where many people do not realise they have it, but there is no easy way to screen for it.

In those with the condition, the cells in the lower gullet become abnormal due to chronic acid reflux, which puts them at a higher risk of developing cancer of the oesophagus.

Doctors can screen those at risk using an endoscope - a flexible tube containing a tiny video camera - but this is unpleasant and usually has to be done under sedation.

Tiny capsule

The new device is contained in a capsule about the size of a multivitamin pill connected by a thin wire.

Within the capsule is a rapidly rotating laser tip which emits infrared light that is then reflected back from the lining of the oesophagus.

When the patient swallows the capsule it is carried down the oesophagus in the same way any piece of food would be then once it reaches the stomach it can be pulled back out using the wire.The image doctors see on the screen is a 3D landscape showing far more microscopic detail than can be seen with endoscopy.

Images are taken the whole time the device is moving up and down the gullet and the whole process takes a matter of minutes.

Testing the equipment in six patients known to have Barrett's oesophagus and seven healthy volunteers, the researchers said the images clearly showed the cellular changes that occur in those with the condition.

'Best pictures'

Prof Gary Tearney, one of the research collaborators, said the technology is cheaper than endoscopy and avoids the need for sedation, specialised equipment or special training.

And the microscopic detail shown in the images means a biopsy can be avoided.

"The images produced have been some of the best we have seen of the oesophagus," says Prof Tearne, a professor of pathology at Harvard Medical School.

"We originally were concerned that we might miss a lot of data because of the small size of the capsule, but we were surprised to find that, once the pill has been swallowed, it is firmly 'grasped' by the oesophagus, allowing complete microscopic imaging of the entire wall."

Prof Tearney added that the device could help doctors work out who is at risk and detect cancers at potentially more treatable stage.

Prof Rebecca Fitzgerald, a specialist on Barrett's oesophagus at the Cambridge Cancer Centre, said: "It is elegant technology. The downside is that you will have to endoscope anyone with suspected Barrett's as you will have no way of sampling and detecting dysplasia [abnormalities] with this technology."

READMORE:http://www.bbc.co.uk/news/health-20983324

Fast-food 'linked to childhood asthma and eczema'

Eating fast food three times a week may lead to asthma and eczema in children, say researchers who have looked at global disease and dietary patterns.

Data from more than 500,000 children in more than 50 countries suggests poor diet may be to blame for rising levels of these allergy-related conditions.

Those who ate fast food, such as take-away burgers, risked severe asthma, eczema and itchy, watery eyes.

Eating plenty of fruit appears to be protective, Thorax journal reports.

Fast food often contains high levels of saturated- and trans-fatty acids, which are known to affect immunity, while fruit is rich in antioxidants and other beneficial compounds, say the researchers.

In the study, children in their early teens who ate three or more weekly servings of fast food had a 39% increased risk of severe asthma.

Six- and seven-year-olds had a 27% increased risk.

Eating three or more portions of fruit a week cut the risk of severe asthma, eczema and rhinoconjunctivitis by between 11% and 14%.

The study authors, Prof Innes Asher, from the University of Auckland in New Zealand, and Prof Hywel Williams, from the University of Nottingham in the UK, said: "If the associations between fast foods and the symptom prevalence of asthma, rhinoconjunctivitis and eczema is causal, then the findings have major public health significance owing to the rising consumption of fast foods globally."

Generally, people with asthma do not have to follow a special diet.

In some cases, certain foods, such as cow's milk, eggs, fish, shellfish, yeast products, nuts, and some food colourings and preservatives, can make symptoms worse.

Malayka Rahman of Asthma UK, said research suggests that a person's diet may contribute to their risk of developing asthma and that eating healthily may have a beneficial effect.

"Evidence suggests that the vitamins and antioxidants found in fresh fruit and vegetables have a beneficial effect on asthma therefore Asthma UK advises people with asthma to eat a healthy, balanced diet including five portions of fruit or vegetables every day, fish more than twice a week, and pulses more than once a week."

READMORE:http://www.bbc.co.uk/news/health-21009654

Delay pregnancy after obesity surgery

Women who have had weight loss surgery should wait at least a year before trying for a baby, experts have warned.

Having a baby after surgery is safer and associated with fewer complications than becoming pregnant when morbidly obese, say doctors.

But patients should still be treated as high-risk and be "strongly advised" not to get pregnant for 12 to 18 months afterwards, a review suggests.

Obesity among women of childbearing age is expected to rise to 28% by 2015.

National guidelines recommend weight loss surgery - most commonly done through a gastric band or gastric bypass - as an option for anyone with a body mass index of more than 40kg/sq m.

The review of the latest evidence, published in The Obstetrician and Gynaecologist journal, says that it will become more and more common for doctors to be asked for advice about the safety of becoming pregnant after bariatric surgery.

Yet there is a lack of guidance on how to manage such patients.

Surgical complications

Researchers found that most women who get pregnant after bariatric surgery would have no complications, with one study suggesting 79% would have a straightforward pregnancy.

But there can be surgical complications with the potential for a gastric band to slip or move during pregnancy, leading to severe vomiting.

One study found that band leakage was reported in 24% of pregnancies.

Women who become pregnant after weight loss surgery should be managed by a team of experts that includes an obstetrician, surgeon, fertility specialist and nutritionist, the review recommends.

The researchers also pointed out that the female patients should receive advice and information before they got pregnant, on contraception, nutrition and weight gain, and vitamin supplements.

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Advising women who have had weight loss surgery to wait at least 12 months before trying to conceive, they pointed to research showing an increased risk of miscarriage.

One study found that 31% of pregnancies occurring within 18 months of having weight loss surgery ended in spontaneous miscarriage compared with 18% in women who got pregnant after 18 months.

Rahat Khan, consultant obstetrician and gynaecologist at Princess Alexandra Hospital NHS Trust in Harlow, Essex, and co-author of the review, said this issue was affecting an increasing number of women of childbearing age.

"In light of current evidence available, pregnancy after bariatric surgery is safer, with fewer complications, than pregnancy in morbidly obese women," she said.

But she added this group of women should still be considered to be high risk.

Daghni Rajasingam, of the Royal College of Obstetricians and Gynaecologists, said obesity was associated with a number of serious risks in pregnancy, and women should be supported to lose weight before conception.

"It is important that women are aware of the increased risk of maternal and fetal complications associated with obesity, and they should be advised about the possible strategies to minimise them prior to conception."

READMORE:http://www.bbc.co.uk/news/health-20979355

Mosquitoes Prevent Disease

After a summer of record-high temperatures in the US in 2012, health officials are still dealing with the repercussions of mosquito-borne diseases. Could genetically-modified insects halt their spread?

The year 2012 ended with an ignoble distinction. According to the United States' Centers for Disease Control and Prevention (CDCP), it was the worst year for West Nile virus since 2003.

The CDCP says record-high temperatures could well have helped the mosquitoes that transmit the disease to thrive.

At the same time, new outbreaks of dengue fever on the Mexican side of the Texas-Mexico border had US officials worried that the virus would slowly spread north.

And experts fear that in 2013, it's only going to get worse.

A British company, Oxitec, has come up with a plan to control the bugs and combat dengue fever. Its scientists have designed genetically modified mosquitoes that have one mission - to kill off the rest of their species.

But is the plan too radical for its own good?

A growing problem

The World Health Organization says dengue ranks as the most important mosquito-borne viral disease in the world. In the last 50 years, incidence has increased 30-fold.

It is now endemic in Puerto Rico and in many popular tourist destinations in Latin America and South East Asia.

West Nile virus was first identified in Africa in the 1930s, before spreading out from there and appearing in North America in 1999. It is now widely established from Canada to Venezuela.

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Climate change and globalisation could be major factors behind the increase in mosquito-borne diseases in the US and elsewhere.

Walter Tabachnick, director of the Florida Medical Entomology Laboratory at the University of Florida, says warmer and wetter conditions can make it easier for some mosquitoes to multiply and spread disease.

"Viruses replicate more quickly in mosquitoes and are transmitted more easily when average air temperatures rise and increased rainfall in normally dry areas creates more water pools where mosquitoes can thrive," Mr Tabachnick adds.

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At the same time, greater and faster movement of humans and cargo allows more infected people and mosquitoes to come into contact with previously unaffected populations and areas.

In the US the current method of keeping mosquito populations under control is to spray their larvae with pesticides.

This method is only effective when the larvae can actually be found and reached by the spray. Unsprayed eggs can survive for months before hatching. Meanwhile, resistance to the pesticides among mosquitoes is rising.

Pest-control authorities say spraying can therefore be highly labour intensive, inefficient and expensive.

Enter Oxitec, and their genetically modified mosquitoes.

'Suicide bombers'

These mosquitoes are created by injecting mosquito eggs in the lab with a killer gene. It produces a protein called tTA, which stops the mosquitoes' cells from turning on other genes which are essential for the bugs to survive.

The resulting GM male mosquitoes are then released into the wild to breed with non-GM females, producing offspring genetically programmed to die well before reproductive age.

The company says that as the number of GM males introduced into an environment increases, the lower the chances the non-GM males have of breeding with non-GM females, until eventually the mosquito population can be effectively eliminated.

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Unintentional releases

Oxitec says it has done tests in Brazil, Malaysia and the Cayman Islands, which show mosquito numbers can be greatly reduced in a few months.

"You first release a few thousand males to see if they will mate, then you move to a control programme. In the Cayman Islands we released 3 million over a few months over 16 hectares. We effectively brought the overall mosquito population down by 80% in three months," Oxitec's CEO Haydn Parry told BBC World Service.

While only GM males are intentionally released, critics point out and Oxitec acknowledges that the release of a small number of GM females cannot be avoided. The males are filtered out for release from the generally bigger females, but some females slip through the net. It is only the female mosquitoes which bite and spread disease.

However, Mr Parry says the small number of GM females that do get released present no danger even if they bite humans. "It's exactly the same as being bitten by a wild one," he says. "The gene, or protein, that prevents the next generation from surviving isn't toxic or allergenic and isn't expressed by the saliva glands" and therefore is not injected into humans when they are bitten.

Eric Hoffman, a biotechnology campaigner for Friends of the Earth in the US, says that if tetracycline is present in the wild the offspring of GM mosquitoes could survive and breed.The released GM mosquitoes can breed due to the presence in the lab of the antibiotic tetracycline - which is used in agriculture and found in some meat - which stops the protein from working.

Mr Parry says his company's GM mosquitoes have been shown to be safe and that it would not introduce them where tetracycline exists in the environment. "We created this strain of mosquito more than 10 years ago now. You do a lot of internal testing in labs in a contained environment even before going to an outside environment," he says.

READMORE:http://www.bbc.co.uk/news/world-us-canada-19091880