Scientists may be closer to understanding how genes can influence serious heart conditions, says a Nature Genetics report.

 The failure to turn off a specific gene at the right time in an embryo's development could mean illness later in life.

 Mice in which the gene was left active were born apparently healthy, but suffered heart muscle problems later.

 A heart charity said it might one day be possible to fix the genetic switch.

 The science of "epigenetics", which places importance not just on the genes you carry, but also how well they are working, is a relatively new area.

 There is increasing evidence that suggests that while you carry the same set of genes for life, environmental factors, such as diet or even your mother's health while you are in the womb, could affect their activity, and your chances of certain illnesses later in life.

 The scientists from the Gladstone Institute in San Francisco focused on two genes, and their role in cardiomyopathy, a enlarging and weakening of the heart muscle which is a feature in life-threatening heart defects in children and adults.

 Developing signs

 One of the genes, called Six1, appears to play an important role in embryonic heart development, while the other, Ezh2, seems to have the job of switching off genes, including Six1, when they are no longer needed.

 The researchers tested the precise relationship by stopping Ezh2 from working in the embryo and foetus at various points during pregnancy, thereby allowing Six1 to go on working for longer than usual.

 They found that while the mice were born apparently normal and healthy, they then started to develop the signs of cardiomyopathy.

 This suggested that although leaving Six1 switched on in humans might produce a seemingly healthy baby, it could be storing up heart problems for later in life.

 Analysis of the results revealed that, in a healthy pregnancy, Six1 should only normally be switched on briefly during heart development.

 'Crucial step'

 Dr Paul Delgado-Olguin, one of the team, said: "When Six1 remains active for too long in Ezh2-deficient mice, it boosts the activity of other genes that shouldn't be activated in heart muscle cells - such as genes that make skeletal muscle.

 "The enlargement and thickening of the mice's hearts over time eventually led to heart failure."

 They are hopeful that further work will reveal more about the roots of congenital heart problems in early life.

 Professor Peter Weissberg, from the British Heart Foundation, said the research was "important".

 "What this shows is that a really crucial step in normal heart development is the switching off of genes.

 "If this doesn't happen, and they continue to be expressed, this can cause trouble later in life."

 He said that there was the possibility that faulty gene expression could be corrected, although it would be some years before such techniques could be used in humans.

 The possible reasons for the faulty "switch" - whether dietary, medical or something else - could also be investigated, he added.

 Mass gatherings, such as the London 2012 Olympics, can be a hotbed of diseases from across the world, public health experts have warned.

 They say it can have consequences for the host nation and for people when they return to their own countries.

 There are also important issues to consider in handling large numbers of people, they say.

 A series of reports, in The Lancet Infectious Disease journal, has been highlighting the risks.

 The theory is that so many people, packed closely together, increases the risk of diseases spreading.

 Prof Ibrahim Abubakar, from the University of East Anglia, writes that there are risks from diseases already in the host country and from the home countries of the visitors.

 He highlighted religious or music festivals and major sporting events as mass gatherings which could have a public health risk, such as an influenza outbreak during World Youth Day in 2008 in Australia.

 One report said increased air travel and the spread of diseases could have "potentially serious implications to health, security, and economic activity worldwide".

 Crowds

 The reports also highlight the challenges of managing large numbers of people and pointed to the stampede at the 2010 Love Parade in Germany in which 21 people died and 500 were injured.

 Saudi Arabia has to make careful preparations for the world's largest annual mass gathering - the Hajj, with more than two million pilgrims.

 Prof Ziad Memish, from the country's Ministry of Health, said: "Conventional concepts of disease and crowd control do not adequately address the complexity of mass gatherings.

 "Mass gatherings have been associated with death and destruction - catastrophic stampedes, collapse of venues, crowd violence and damage to political and commercial infrastructure."

 Prof Brian McCloskey, who is in charge of the Health Protection Agency's preparations for London 2012, told the BBC: "The history of the Olympic Games suggests infection doesn't happen often.

 "The issue for us is to make sure the right system is in place to respond."

 He has been improving the agency's disease surveillance to include data straight from hospitals and walk-in centres, which he said would "leave a legacy of probably the most comprehensive disease surveillance system in the world".

 Conjoined twins have been born in Brazil with two heads, two functioning brains and two backbones - but a single heart.

 The rare condition is thought to have occurred when one of the pair failed to fully develop in the womb.

 Doctors say separating the twins, named Jesus and Emanuel, is not currently an option because there is only one set of organs, Reuters reports.

 They are being monitored by specialists to see how they develop.

 Dr Neila Dahas, who is treating the newborns, said surgery was not being considered at the moment.

 But she said separating the boys would be impossible because of the single set of organs - and that it was difficult to choose which head to remove because both brains were functioning well.

 "What we know statistically is that the children who undergo surgery and survive are the children who have less organs in common," she added.

 "What we've got to think about at this moment is to maintain the children in good condition and see how they will develop."

 'No scans'

 The condition, known as dicephalic parapagus, is rare.

 However there have been other known cases, notably Abigail and Brittany Hensel who were born in the US in 1990. They aim to live as normal a life as possible, even taking their driving test when they were 16.

 Jesus and Emanuel were born by Caesarean section weighing 9.9lbs (4.5kg) on Monday morning in a small hospital in the northern state of Para.

 They were then taken by plane to a better equipped hospital in the state capital Belem.

 Doctors say the mother breastfed both boys a few times and that their appetite is normal.

 Claudioner Assis de Vasconcelos, director of the hospital in Anajas where she gave birth, told Brazil's O Povo newspaper that she came in because she was experiencing strong abdominal pains.

 It is reported that the 25-year-old, who lives in a remote area, did not have any ultrasound scans during her pregnancy - and only found out about her sons' condition minutes before the birth.

 Mr de Vasconcelos said: "Despite all the problems we have as a small interior hospital we managed to save both mother and baby, which was our aim."

 Patrick O'Brien, a spokesman for the UK's Royal College of Obstetrician and Gynaecologists who has been involved in several conjoined twin cases, said no decisions were likely to be made about Jesus and Emanuel's future for some time.

 "A lot of work is needed, in terms of scans and tests, before doctors will know if they can separate them or not, and just how organs and blood vessels are shared and linked.

 "It takes quite a while before they can decide how feasible it is."

 Mr O'Brien said dicephalic parapagus affected around one in 100,000 pregnancies, but that around half do not reach full-term.

 A mother-of-three won't be enjoying a tipple during the festivities this year - because just one alcoholic drink could kill her. Joanne Patterson, 41, turned to the bottle after splitting up from her partner.

 She quickly got into a routine of drinking from morning till night and would polish off up to three bottles of wine and numerous cans of lager every day.

 'I'd wake up in the morning and start convulsing. But as soon as I had a couple of glasses of wine I was able to function,' she told The Sun.

 Ms Patterson, from Sunderland, was soon buying alcohol on every supermarket trip and would be unable to put the food away until she had opened a new bottle. She continued to care for her two sons and daughter and assumed she could carry on as she still felt generally well.

 However, after three years her body could no longer take the alcohol abuse and her stomach started to swell.

 She was admitted to hospital where she was diagnosed with chronic liver disease. 'When the doctor said one more drink could kill me I was just mortified. I haven't touched a drop since,' she said.

 Despite Joanne's total change of heart she has suffered irreversible damage to her liver. She has spent 300 days in hospital over the past 18 months and must take up to 100 tablets a week to keep her condition in check.

 Her enlarged liver causes her pain and has made her skin sensitive and itchy. She said doctors have told her her liver can fail at any time and she will need a liver transplant to survive. Ms Patterson's sons are now 21 and 14, while her daughter is seven and she is desperately hoping she will get to see them grow up.

 She added that she wanted her case to be a stark warning to others. 'I never thought I would get this much damage from drinking,' she said.

 'I have destroyed my life.'

 Dr Susanne Ludgate: "We would really advise women in this country not to panic

 Women with silicone breast implants made by a French company should not have them removed, UK officials say.

 French authorities will decide shortly whether women should have implants supplied by Poly Implant Prothese (PIP) removed, amid fears of health risks.

 But the UK's Medicines and Healthcare products Regulatory Agency (MHRA) says none of the evidence into possible links with cancer supports removal.

 It is thought up to 40,000 British women have the PIP silicone implants.

 Women with implants who are concerned have been told to contact the surgeon or clinic that fitted them. According to the MHRA, the vast majority (95%) of the implants were fitted privately, with less than 5% used within the NHS.

 In the UK, more than 250 British women are to start legal action, said a lawyer. Over half had suffered ruptured implants, Esylllt Hughes told the news agency AFP.

 PIP used non-medical grade silicone believed to be made for mattresses, according to the British Association of Aesthetic Plastic Surgeons (BAAPS). This meant the low-cost devices were more likely to split.

 'Seek advice'

 Eight cases of cancer, mainly breast cancer, had so far been reported in patients with PIP implants, France's Director General for Health, Jean-Yves Grall, told the Liberation newspaper. A ninth patient in Gers died of cancer last year.

 But the head of France's National Cancer Institute, Dominique Maraninchi, said last week the cases were not necessarily linked to faulty implants.

 The MHRA said there was "insufficient evidence to indicate any association with cancer" after reviewing the available evidence with the relevant UK professional bodies.

 It said it had worked in consultation with the cancer registry as well as professional bodies for breast surgery and surgical oncology.

 "The MHRA's current advice to women with any type of breast implant continues to be that women who are concerned about their breasts or think that their implants may have ruptured, should seek clinical advice from their implanting surgeon," the agency said.

 A statement from the British Association for Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS) said: "BAPRAS has not yet seen the evidence demonstrating that health problems may have been caused by PIP breast implants and will fully assess any that becomes available.

 "We currently believe that the expected announcement from French medical authorities will be a precautionary measure.

 "Surgeons will be in contact with any patient who has received this type of implant if any action is required."

 Douglas McGeorge, consultant plastic surgeon and former president of the British Association of Aesthetic Plastic Surgeons (BAAPS), said patients with breast implants should check whether they have had one from PIP.

 "The message here is not to panic," he said.

 "The advice is unchanged. Women with PIP implants should be checked by the clinic where they had their surgery and can then be monitored afterwards.

 "These implants have a higher failure rate so there will be women who might choose to have their implants removed before that happens, whereas others will be happy to be monitored."

 Encouraging an overweight partner or close friend to shed some pounds could be your best gift to them this Christmas. Yet a recent UK poll finds that while most people worry that an excessive waistline might be affecting their loved one's health, a considerable number shy away from raising the matter with them.

 The International Chair on Cardiometabolic Risk (ICCR), an academic organization based at Université Laval in Quebec City, Canada, commissioned the poll to highlight the risk of being overweight, particularly around the waist.

 Carrying too much fat around the waist raises the risk of developing type 2 diabetes, coronorary heart disease, and stroke.

 This type of fat (called "visceral fat") is metabolically more active than fat located under the skin and can trigger reactions in the body that disturb metabolic processes.

 According to a BBC News report, Dr Jean-Pierre Després, scientific director of the ICCR, told the media:

 "Earlier this year, ICCR found that 41% of Britons do not realise that having fat around their waistline is worse for their health than fat stored elsewhere on the body."

 The poll, which was also supported by the National Obesity Forum (NOF), an organization of UK medical practitioners concerned about the growing effects of being overweight on patients and the National Health Service (NHS), surveyed more than 2,000 people.

 The survey found that while 59% of people worried that a loved one's excess waistline would lead to serious health problems, too many would shy away from telling them their concerns for fear of hurting their feelings.

 It also found differences between men and women as to which loved ones they would have the most difficulty confronting, and there were also differences across age groups.

 For example: 31% of men would shy away from telling their partners they should lose weight compared with only 10% of women.

 Women were more hesitant about confronting a close friend: 23% would shy away from telling a close friend they needed to lose weight compared to only 8% of men.

 42% of people aged 18 to 24 would shy away from telling a loved one they should lose weight, compared with just over a third of 25 to 44-year-olds and about a quarter of those older than this. Professor David Haslam, chair of the National Obesity Forum, says suggesting to a loved one with a large waistline that they should think about shedding a few pounds might not be a comfortable conversation, but:

 "... as long as you do it sensitively, discussing it with them now could help them avoid critical health risks later down the line and could even save their life."

 Després agrees, emphasizing that this is "about health not vanity", and you should start by encouraging them to "make simple lifestyle changes such as becoming more active, making small alterations to their eating habits and replacing sugary drinks for water".

 Studies show that weight loss caused by a low-calorie diet or exercise program can significantly reduce abdominal fat. The extend of the reduction depends on how overweight the person is and where their fat is distributed, but generally, the more excess abdominal fat they carry, the more they lose.

 On their website myhealthywaist.org, the ICCR say several studies show that losing as little as 5 to 10% of initial body weight can reduce fat in the abdomen by 10 to 30%.

 Exercise is also important: for a given amount of weight loss, it burns more fat around the waist than calorie restriction, while preserving lean body mass or muscle.

 Thus, it is entirely possible, with exercise, to lose fat around the waist without actually losing weight.

 So, when you step on those bathroom scales, grab a tape measure and check your waist size as well.

 For men, the waist should be no larger than 94 cm (37 in) and for women it should be no more than 80 cm (31.5 in).

 The risk of developing cancer in middle-age has risen by over 20% in a generation, figures from a cancer charity suggest.

 The Cancer Research UK data show that in Britain in 1979, 44,000 people aged 40-59 developed the disease, compared with 61,000 in 2008.

 CRUK said the rise for men and women was partly due to better screening, but also lifestyle factors like obesity.

 However cancer survival rates have improved, doubling since the late 70s.

 Last week, Macmillan Cancer Support warned overall cancer incidence had risen from a third to four in 10 people.

 This latest analysis shows cases among the middle-aged increased from 329 per 100,000 to 388 per 100,000.

 And among women in their 40s and 50s, cancer rates have risen by more than 25% - from 24,000 in 1979 to more than 36,500 in 2008.

 Breast cancer rates increased by 50%.

 In middle-aged men, prostate cancer rates rose six-fold over the same period.

 Earlier diagnosis

 The increasing number of people being diagnosed is, in part, due to the NHS breast screening programme and the PSA test for prostate cancer.

 Lifestyle factors have also influenced cancer rates.

 In women, use of the contraceptive Pill, drinking more alcohol, having children later and being overweight have increased breast cancer risk.

 Skin cancers are also on the up in both men and women, due to people spending more time in the sun.

 But improvements in screening does mean cancers can be detected earlier, and therefore treatment - which has also improved - is more likely to be successful.

 Harpal Kumar, chief executive of Cancer Research UK's, said: "There has been undeniable progress in the treatment of cancer over the last 40 years and many more people are surviving the disease.

 "But we must redouble our efforts to ensure that our research continues to discover new techniques to improve and refine diagnosis and treatment so that cancer survival becomes the norm for patients, irrespective of the cancer they have or their age at diagnosis."