Study Links Soy to Lower Sperm Counts

Eating even small amounts of soy products may cut a man's sperm concentration, a study published online last Thursday in the journal Human Reproduction shows.

Of the 99 men enrolled in the study, those who said they ate the most soy had much lower sperm concentrations than those who reported eating no soy. Soy eaters had, on average, 41 million fewer sperm per milliliter than those who avoided soy products. That association held up after other factors potentially affecting sperm health, such as smoking, alcohol and caffeine intake, age, abstinence time and body mass index were considered.

Still, a man starting with an average sperm count (80 million to 120 million per milliliter) and experiencing such a reduction would measure well above the 20 million that is the minimum count within the normal range, says lead author Jorge Chavarro, a research fellow in the department of nutrition at the Harvard School of Public Health.

Consumption of the study's 15 soy-based foods, from miso soup and tofu to soy burgers, ice cream and energy bars, was low, an average of one serving every other day among the highest-consuming group.

Soy contains isoflavones, which have long been tied to infertility in animal studies.

The study is the largest to look at soy's effect on human male fertility; its findings conflict with those of previous studies, one of which found no relationship between the two and another that found soy consumption actually boosted sperm counts.

Given those conflicts, Chavarro says, "I think there is not enough evidence to reach any strong conclusion or advise men one way or the other on whether soy foods can affect their fertility."

Source: www.washingtonpost.com

Hour's exercise 'to lose weight'

Women who want to lose weight - and keep it off - need to be exercising for almost an hour, five days a week, according to US experts.

The University of Pittsburgh study found the 55-minute regime was the minimum needed to maintain a 10% drop in weight.

Only a quarter of the 200 women in the study managed to lose this amount.

A UK expert said it was clear that regular moderate exercise was the way to lose weight, and keep it off.

Approximately two-thirds of adults in the UK are overweight or obese, with some estimates suggesting this could rise to nine in ten by 2050.

Research points to a combination of exercise and calorie control as having the best chance of success in weight loss - although the majority of people who attempt these diets fail to keep the weight off.

The latest research, published in the Archives of Internal Medicine journal, confirms that plenty of exercise is a key ingredient of success.

The Pittsburgh researchers looked at a group of overweight and obese women over a four year period.

They were all told to eat between 1,200 and 1,500 calories a day, and split into four different exercise programmes, varying the intensity and amount of exercise carried out.

After six months, women in all four groups had lost up to 10% of their body weight - but most could not keep this going.

The women who did maintain the 10% loss were those who reported doing more exercise, on average 275 minutes per week.

Hour target

In the UK, everyone is encouraged to manage at least 30 minutes of moderate exercise five days a week, but scientists say that people wanting to maintain weight loss need much more.

Professor Paul Gately, a specialist in exercise and obesity, from Leeds Metropolitan University, said: "This study is excellent - it's the best evidence that this higher level of exercise is needed.

"Thirty minutes a day is good for general health, but if you want to lose weight, you need to be doing more, and if you want to sustain weight loss, you need to be doing even more than that.

"In this country, between an hour and 90 minutes of exercise a day is the recommended level for maintaining weight loss."

He said that "moderate" exercise covered anything that made you slightly breathless, from brisk walking to gardening.

Some US researchers have been looking at novel ways to increase the level of activity among those with "couch potato" lifestyles.

Dr James Levine is helping develop the "Walkstation", a computer terminal with a treadmill instead of a chair.

Writing in the same journal, he said: "Sitting at one's desk uses barely any more calories than staying in bed, but walking at 1mph while working increases caloric expenditure by approximately 125 calories an hour."

Source: news.bbc.co.uk

The Reason Fat People Find It Hard to Lose Weight Is Found

The reason fat people find it hard to lose weight is found.

The difference in the number of fat cells between lean and obese people is established in childhood and, although fat people replenish fat cells at the same rate as thin ones, they have around twice as many.

This remarkable glimpse of what gives us beer guts, love handle and muffin tops could also lead to new approaches to fight the flab, by cutting the overall number of fat cells in the body, as well as providing an insight into why fat people find it so hard to lose weight, because the number of fat cells in a person remains the same, even after a successful diet.

The details of how humans regulate their fat mass is reported today in the journal Nature by a team led by scientists at the Karlolinksa Institute, Stockholm, Sweden, as a second team, led by Imperial College London, reports in the journal Nature Genetics the discovery of a gene sequence present in half the population linked to three quarters of an inch bigger waistline, four lb gain in weight, and a tendency to become resistant to insulin, which can lead to type 2 diabetes.

The fundamental new insight into the cause of obesity comes from an international team lead by Dr Kirsty Spalding, Prof Jonas Frise'n and Prof Peter Arner who found the body constantly produces new fat cells to replace equally rapid break down of the already existing fat cells due to cell death.

They also show, that overweight people generate and replace more fat cells than do lean - and that the total number of fat cells stays equal after a diet program.

Until now, it was not clear that adults could make new fat cells. Some had assumed that they increase their fat mass by incorporating more fats into already existing fat cells in order to maintain their body weight (lean, overweight, obese). However now it seems we constantly produce new fat cells irrespective of our body weight status, sex or age.

"The total number of fat cells in the body is stable over time, because the making of new fat cells is counterbalanced by an equally rapid break down of the already existing fat cells due to cell death", says Prof Arner.

The study was made possible by a method to use radioactive isotopes in fat cells from people who had lived through the brief period of Cold War nuclear bomb testing from 1955 to 1963 to determine the age of the fat cells in the body.

This was combined with methods to carefully measure the size of the fat cells in relation to the total amount of adipose tissue in 687 people with a large individual variation in body weight who had undergone liposuction and abdominal reconstruction surgery.

Fat cells are replaced at the same rate that they die - roughly 10 per cent every year. The level of obesity is determined by a combination of the number and size of fat cells, which can grow or shrink as fat from food is deposited in them.

Even if obese subjects go on a diet they keep the total number of fat cells in the body constant, but the size of individual fat cells is decreased markedly.

The findings therefore provide a new target for treatment of obesity, namely by attacking the signals and genes in fat cells that control the formation of new such cells.

"The results may, at least in part, explain why it is so difficult to maintain the weight after slimming", adds Prof Arner.

"Until now it was not clear whether there was fat cell turnover in adults," adds Dr Spalding. "Now we have established this does occur, we can target the process.

"Various groups are looking at compounds that might regulate the formation of fat cells but this work is at too early a stage to say when anti obesitiy drugs based on this understanding will be tested on patients, if at all."

Other new insights into how to treat obesity could come from the gene sequence linked to an expanding waist line, weight gain and a tendency to develop type 2 diabetes in the Imperial led study.

Professor Jaspal Kooner, the paper's senior author from the National Heart and Lung Institute at Imperial College London, says: "Finding such a close association between a genetic sequence and significant physical effects is very important, especially when the sequence is found in half the population."

The study shows that the sequence is a third more common in those with Indian Asian than in those with European ancestry. This could provide a possible genetic explanation for the particularly high levels of obesity and insulin resistance in Indian Asians, who make up 25 per cent of the world's population, but who are expected to account for 40 per cent of global heart disease by 2020.

The new gene sequence sits close to a gene called MC4R, which regulates energy levels in the body by influencing how much we eat and how much energy we expend or conserve. The researchers believe the sequence is involved in controlling the MC4R gene, which has also been implicated in rare forms of extreme childhood obesity.

Previous research on finding the genetic causes of obesity has identified other energy-conserving genes. Combining knowledge about the effects of all these genes could pave the way for transforming how obesity is managed.

This research, backed by the British Heart Foundation, was carried out with scientists from the University of Michigan and the Pasteur Institute, France.

Last year a British led team found that if people carry one copy of a variant in a gene called FTO, as does half of the general population, it will lead to a gain in weight of 2.6lb or put just over half an inch on their waists and raise their risk of being obese by one third.

If people have two copies of this variant in the FTO gene, which is the case in one in six of the population, then they will gain almost 7lb more than those who lack the variation and are at a 70 per cent higher risk of obesity.

According to the 2001 Health Survey for England, more than a fifth of males and a similar proportion of females aged 16 and over were classified as obese.

Half of men and a third of women were classified as overweight.

Source: www.telegraph.co.uk

Younger Women Often Miss Signs of Heart Attack

Many younger women ignore or simply don't recognize the warning signs of a heart attack, often because it doesn't resemble the typical "Hollywood heart attack."

So say the authors of a study being presented Friday at the American Heart Association's annual Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke, in Baltimore.

"So many women said, 'We wish we had a better stereotype, you never see anything in the media,'" said study author Judith Lichtman, an associate professor of epidemiology and public health at Yale School of Medicine. "I personally would love to see some cutting-edge TV series of, for example, a young person having a heart attack with atypical symptoms."

"The classic image of someone having a heart attack is someone like John Belushi. It's a heavy man clutching his chest. We never think of young women as having heart disease, so the image is not part of their consciousness," added Dr. Suzanne Steinbaum, director of Women & Heart Disease at Lenox Hill Hospital in New York City. "It's so important that we not only tell women that heart disease doesn't necessary have to look like [a Hollywood script], but they have to understand what makes them at risk."

Heart disease is the leading killer of American women, claiming almost half a million lives a year, or about one death per minute. According to background information from the authors, 16,000 young women with heart disease die every year and 40,000 are hospitalized.

Last year, a study from the same group of researchers found that women under the age of 55 often fail to recognize the symptoms of a heart attack until it's too late.

Eighty-eight percent of women in that trial reported traditional symptoms of severe chest pain. Yet only 42 percent suspected something was wrong with their heart.

Only half of the women experiencing heart attack symptoms sought care within the first hour, apparently because they thought their symptoms weren't real or weren't serious.

For this study, researchers conducted in-depth interviews with 30 women aged 55 and older a week after they had been discharged from the hospital following a heart attack.

Many didn't realize the symptoms were due to a heart attack. For example, one woman said she was told she was experiencing symptoms of acid reflux. Others attributed symptoms to fatigue, overexertion or stress.

Often, the symptoms just didn't line up with how heart attacks are presented in the popular media.

"I had probably seen a show or something with somebody having a heart attack," said one woman. "And they fall. They grab their chest. And then they grab their arm... I mean, you don't see anybody saying I have pain in my jaw or especially a heart attack, you don't see them vomiting... I did not know that and it's probably because of television, I would say is why I thought it would just be in the chest."

Similarly, another woman told investigators, "It's like... I didn't have any of the typical heart attack symptoms that you always hear about on TV and the ER hospital shows."

Some delayed treatment because symptoms went away for a while, or because they were too busy or had experienced prior, negative encounters with the health-care system ("...they throw you out, you know," said one woman. "If you don't have the money right there, then in two days you're gone").

One woman said she called her doctor about chest pains but was scheduled for a regular appointment in five days. Another woman who went to the emergency room spent an hour trying to find a supervisor to help her after a "rude" nurse just kept telling her to have a seat.

"A lot of women were triaged for a regular visit or, even in the ER, were being looked up for a lot of things other than a heart attack," Lichtman said.

Ironically, for some women, it was actually a relief to know that they were having a heart attack, that finally the mystery was over, Lichtman said.

Lichtman and her colleagues will be looking at this issue in more depth in a U.S. National Institutes of Health-funded study enrolling 2,000 women under 55 and 1,000 men in the same age range.

"A little bit of empowerment goes a long way," Steinbaum said. "Knowing your risk and knowing the potential for heart disease, seeking early care for symptoms that are really unclear and then saying, 'I am at risk for heart disease, please help me' becomes important in the paradigm of how this needs to develop."

Source: www.washingtonpost.com

Chocolate May Cut Diabetes Risk

Scientists are to investigate whether eating chocolate can reduce the risk of heart disease in women with diabetes.

Volunteers - postmenopausal women with type 2 diabetes - will be asked to eat a bar of chocolate a day for a year.

Cocoa is rich in compounds called flavonoids, which are thought to benefit the heart.

The University of East Anglia is using a specially formulated form of chocolate which contains more flavonoids than usual.

This compensates for the fact that many flavonoids are destroyed in the process of turning cocoa into chocolate.

Soy - another source of flavonoids - has also been added to the special bars.

The scientists are testing the theory that adding flavonoids to the diet may give added protection against heart disease on top of that provided by prescription drugs.

Deaths due to heart disease among women increase rapidly after the menopause and having type 2 diabetes increases this risk by a further three-and-a-half times.

If the trial confirms the hypothesis then it could have a far-reaching impact on the advice given to at-risk women.

Additional protection

Lead researcher Professor Aedin Cassidy said: "Despite postmenopausal women being at a similar risk to men for developing cardiovascular disease, to date they are under-represented in clinical trials.

"We hope to show that adding flavonoids to their diets will provide additional protection from heart disease and give women the opportunity to take more control over reducing their risk of heart disease in the future."

The researchers aim to recruit 150 women under the age of 70 with type 2 diabetes who have not had a period for at least a year, and who have been taking cholesterol-lowering statin drugs for at least 12 months.

Dr Iain Frame, director of research at the charity Diabetes UK, said: "We certainly don't advise people to start eating a lot of chocolate as it is very high in sugar and fat.

"We would always recommend that people with diabetes eat a diet low in fat, salt and sugar with plenty of fruit and vegetables."

"However, there are compounds found in chocolate, called flavonoids, that are thought to provide some protection from heart disease.

"A successful outcome of this research would hopefully mean being able to offer people at high risk better protection over and above that provided by conventional drugs."

Source: news.bbc.co.uk

Use of Hypertension Drugs Leads to Hip Bone Loss in Older Men

Powerful diuretics, commonly prescribed drugs for heart failure and hypertension, can also steal calcium from the bones and cause significant bone loss in men taking them, study finds.

Between 2000 and 2002, Dr. Lionel S. Lim of Griffin Hospital, in Derby, Connecticut and colleagues tested the bone mineral density levels of 3,269 men older than age 65. Patients received follow-up examinations about 4.6 years later. The researchers collected data on medication use and found that 84 men were continuous users of loop diuretics, 181 were intermittent users and 3,004 were non-users.

At the end of the study, the researchers found that the average annual rate of decline in total hip bone mineral density was -0.78 among continuous users, -0.58 among intermittent users and -0.33 among nonusers.

“Compared with rates of hip bone loss among non-users of diuretics, adjusted rates of loss were about twofold greater among intermittent loop diuretic users and about 2.5-fold greater among continuous loop diuretic users,” wrote Dr. Lim and colleagues in the study.

These findings come to reinforce previous studies, which have found an association between the use of powerful diuretics and increased risk of fractures.

“We conclude that loop diuretic use in older men is associated with increased rates of hip bone loss. Our findings suggest that health care providers should take into account loop diuretic use when evaluating older men for risk factors for bone loss and fracture risk,” the study wrote.

The findings were similar for change at the femoral neck and trochanter, the researchers said.

The study, supported by the national Institute of Health, was published in the April 14 issue of the Archives of Internal Medicine.

Source: eFluxMedia.com

Early Dementia Often Caused by Autoimmune Disorders

Dementia in patients who are younger than 45 years of age is often caused by degenerative, metabolic or autoimmune diseases, Dr. Brendan Kelley, of the Mayo Clinic in Rochester, Minnesota, told attendees at the 60th annual meeting of the American Academy of Neurology, being held this week in Chicago.

Kelley and colleagues searched the Mayo Clinic database for patients who began to develop dementia between 17 and 45 years that was not related to trauma, brain infections or mental retardation. They identified 235 such patients receiving care between 1996 and 2006. The average age at dementia onset was 34.7 years.

Neurodegenerative causes accounted for dementia in 29.8 percent of the group, frontotemporal dementia occurred in 13.2 percent and Alzheimer's disease was seen in less than 1 percent," data presented by Kelley showed.

Autoimmune-inflammatory causes, including multiple sclerosis, accounted for 21.2 percent. Inborn errors of metabolism were identified in 10.6 percent.

At the last evaluation, the cause of dementia was still unknown in 44 patients (18.7 percent) despite exhaustive evaluations, Kelley reported.

Inborn errors of metabolism were more common in individuals with symptoms appearing before age 30. Neurodegenerative causes were more common in dementias occurring after age 35.

"Some of the important causes, such as lupus, metabolic disorders, Huntington chorea, among others, can occur in very young children," Kelley told Reuters Health. "Only 4 of the 235 cases in our series resembled Alzheimer's type dementia."

"It is important to increase awareness that dementia can and does occur in young patients," Kelley continued. "This is important for social services and other aid-giving organizations to know."

"Symptoms in younger patients have more of a neuropsychiatric focus, with a lot of psychiatric features," he said. These patients can be misdiagnosed with psychiatric disorders, such as schizophrenia.

The causes of young-onset dementia are more often hereditary or genetic than they are in older patients with dementia.

"We are now looking to determine which clinical features are more classic...which clinical features to focus on," Kelley said. "This is a single disorder with multiple underlying causes. Treating the causes may correct to some extent the disorder."

www.reuters.com

Hypertension Prevents Migraines

Despite being the cause of many serious health problems, high blood pressure seems to have great benefits when it comes to migraines, as new research showed.

Dr. Eling Tronvik of the Norwegian National Headache Center at Trondheim University Hospital in Norway and his colleagues found that high blood pressure seems to reduce the chances of migraine, besides decreasing the quantum of chronic pain in other parts of the body.

It was long believed that migraines and other types of headaches are more common among people with high blood pressure, but studies conducted in the 1990s did not support this belief.

“This is a paradox. Several earlier studies have linked increasing blood pressure to a decrease in chronic pain in general, and this study suggests that the same is true for migraines,” Dr. Tronvik told WebMD.

The study’s data included information on blood pressure, use of blood pressure medications and headache frequency for 51,353 adults living in Norway in the 1980s and 1990s.

The biggest benefit was found in people with the highest pulse pressure, a measurement of the difference between the diastolic and systolic pressure at the moment the heart beats. They had up to 50 percent fewer headaches.

People with high systolic pressure also appeared to do better.

Things looked differently for people who took medicine to control their blood pressure, even though these drugs are often given to migraine sufferers.

“Higher pulse was linked to up a 50 percent reduction in the amount of headache and migraine for both men and women. The finding was not as strong, however, for people who were taking blood pressure medication, which are sometimes used to treat migraines,” Dr. Tronvik said.

How is that possible? Dr. Tronvik explained that high systolic blood pressure and pulse pressure are related to stiff arteries, which affect something called baroreflex arch.

“Both animal and human studies suggest that stimulation of the baroreflex arch can inhibit pain transmission. So changes in blood pressure may affect headache and migraine.”

However, Dr. Tronvik said, no matter how well high blood pressure prevents headaches, people should not abandon their hypertension medications. “High blood pressure is a huge problem in this country, and far too few people are controlling it as they should.”

The findings of the study were published in Tuesday’s issue of Neurology.

eFluxMedia.com

Pneumonia 'linked' to pollution

High levels of pollution may have contributed to the deaths of thousands of people in England from pneumonia in recent years, a study suggests.

A team at the University of Birmingham examined death rates from the disease and pollution levels in 352 local authorities between 1996 and 2004.

Writing in the Journal of Epidemiology and Community Health, they reported a "strong correlation" between the two.

But the researchers conceded that social factors may also be at play.

Calculations were made by looking at how many deaths there were in each locality in excess of the national average.

These figures were then cross-checked with a range of pollutant levels, including engine exhaust emissions.

Culprit car

In total, 386,374 people died of pneumonia during the eight years examined, but there were significant regional variations. Lewisham in London had the highest number of deaths per head, Berwick-on-Tweed the least.

In the 35 local authorities with the highest rates of pneumonia, there were 14,718 more deaths than the national average.

These areas also tended to see higher rates of some cancers, chronic obstructive pulmonary disease (COPD) and rheumatic heart disease.

"High mortality rates were observed in areas with elevated ambient pollution levels," said Professor George Knox, who wrote the report. "The strongest single effect was an increase in pneumonia deaths."

He added: "Road transport was the chief source of the emissions responsible, although it was not possible to discriminate between the different chemical components".

The team estimated that the annual number of excess deaths - or those which could be attributed to the pollution - could approach those of the 1952 London smog, which killed 4,000 people.

But lung specialists said more detailed research was needed before a clear link between pneumonia and exhaust fumes was declared.

"What this paper does show, however, is that there is clear geographical variation in deaths from pneumonia, lung cancer and COPD," said Richard Hubbard of the British Lung Foundation.

"This would suggest that social factors such as deprivation and smoking, and possibly pollution, are important and that there is great potential to prevent deaths from lung disease."

Source: news.bbc.co.uk

Satisfactory Sex Can Be Achieved In A Matter Of Minutes

Survey findings released this week dispel the commonly held fantasy that satisfactory sex requires a significant time commitment. The survey, conducted at Penn State by the Society for Sex Therapy and Research, revealed that satisfactory sex for couples typically lasts 3 to 13 minutes. Movies, television, books and the internet have convinced many couples that if they aren’t having sex “all night long:” their sexual life is in the pits and they are missing out on something significant.

The survey included information garnered from psychologists, physicians, social workers, marriage/family therapists and nurses who have collectively seen thousands of patients over a period of several decades. According to the survey data, 3-7 minutes of intercourse is categorized as “adequate,” 7-13 minutes is “desirable,” 1-2 minutes is “too short” and 10-30 minutes is “too long.”

“A man’s or woman’s interpretation of his or her sexual functioning as well as the partner’s relies on personal beliefs developed in part from society’s messages, formal and informal,” the researchers said. “Unfortunately today’s popular culture has reinforced stereotypes about sexual activity. Many men and women seem to believe the fantasy models of large penises, rock-hard erections and all-night-long intercourse.”

“This seems to be a situation ripe for disappointment and dissatisfaction,” said lead author Eric Corty. “With this survey, we hope to dispel such fantasies and encourage men and women by providing realistic data about acceptable intercourse, thus preventing sexual disappointments and misfunctions.”

Source: medheadlines.com

Cell Phones Bad For Your Health – Again

We’ve heard the pros and cons before, but a new Australian study claims cell phones could be worse for your health than smoking or asbestos.

It’s the issue that won’t go away. Are cell phones detrimental to your health? Will the electromagnetic radiation cause brain tumors? Studies have said yes, studies have said no.

Now a new paper from a staff specialist neurosurgeon at the Canberra Hospital and associate professor of neurosurgery with Australian National University Medical School, Vini G. Khurana, entitled "Mobile Phones and Brain Tumors – A Public Health Concern", looks at the results of previous reportage in both the academic and popular press.

Khurana’s warning is quite dire:

“It is anticipated that this danger has far broader public health ramifications than asbestos and smoking, and directly concerns all of us, particularly the younger generation, including very young children.”

The latency time, he believes, “may be in the order of 10-20 years.” He feels that “the link between mobile phones and brain tumours should no longer be regarded as a myth. Individual and class action lawsuits have been filed in the USA, and at least one has already been successfully prosecuted, regarding the cell phone-brain tumour link.”

However, it’s worth noting that many studies have yet to establish a link between the use of cell phones and cancer.

Source: digitaltrends.com

Emotion Makes Nose a Sharper Smeller

Know how a whiff of certain odors can take you back in time, either to a great memory or bad one? It turns out emotion plays an even bigger role with the nose, and that your sense of smell actually can sharpen when something bad happens.

Northwestern University researchers proved the surprising connection by giving volunteers electric shocks while they sniffed novel odors.

The discovery, reported in Friday's edition of the journal Science, helps explain how our senses can steer us clear of danger. More intriguing, it could shed light on disorders such as post-traumatic stress syndrome.

"This is an incredibly unique study," said Dr. David Zald, a Vanderbilt University neuroscientist who studies how the brain handles sensory and emotional learning. "We're talking about a change in our perceptual abilities based on emotional learning."

Scientists long have known of a strong link between the sense of smell and emotion. A certain perfume or scent of baking pie, for instance, can raise memories of a long-dead loved one. Conversely, a whiff of diesel fuel might trigger a flashback for a soldier suffering PTSD.

Could an emotionally charged situation make that initial cue be perceived more strongly in the first place?

The research team recruited 12 healthy young adults to find out.

Volunteers repeatedly smelled sets of laboratory chemicals with odors distinctly different from ones in everyday life. An "oily grassy" smell is the best description that lead researcher Wen Li, a Northwestern postdoctoral fellow in neuroscience, could give.

Two of the bottles in a set contained the same substance and the third had a mirror image of it, meaning its odor normally would be indistinguishable. By chance, the volunteers correctly guessed the odd odor about one-third of the time.

Then Li gave the volunteers mild electric shocks while they smelled just the odd chemical. In later smell tests, they could correctly pick out the odd odor 70 percent of the time.

MRI scans showed the improvement was more than coincidence. There were changes in how the brain's main olfactory region stored the odor information, essentially better imprinting the shock-linked scent so it could be distinguished more quickly from a similar odor.

In other words, the brain seems to have a mechanism to sniff out threats.

That almost is certainly a survival trait evolved to help humans rapidly and subconsciously pick a dangerous odor from the sea of scents constantly surrounding us, Li said. Today, that might mean someone who has been through a kitchen fire can tell immediately if a whiff of smoke has that greasy undertone or simply comes from the fireplace.

But the MRI scans found the brain's emotional regions did not better discriminate among the different odors, Li noted. That discrepancy between brain regions is where anxiety disorders may come in. If someone's olfactory region does not distinguish a dangerous odor signal from a similar one, the brain's emotional fight-or-flight region can overreact.

Researchers say that is a theory not yet tested.

For now, Northwestern neuroscientist Jay Gottfried, the study's senior author, says the work illuminates a sense that society too often gives short shrift.

"People really dismiss the sense of smell," said Gottfried, who researches "how the brain can put together perceptions of hundreds of thousands of different smells. ... Work like this really says that the human sense of smell has much more capacity than people usually give it credit."

Source: www.foxnews.com

Sex Ed Can Help Prevent Teen Pregnancy

Comprehensive sex education may help reduce teen pregnancies without increasing levels of sexual intercourse or sexually transmitted diseases.

So find U.S. researchers who reviewed data from a 2002 national survey of more than 1,700 heterosexual teens, ages 15 to 19.

There is ongoing debate about whether abstinence-only education or comprehensive sex education (including instruction in birth control) is best for students.

Study lead author Pamela Kohler, a program manager at the University of Washington in Seattle, and colleagues found that about 25 percent of teens received abstinence-only education and about two-thirds received comprehensive sex education. About 9 percent - particularly teens from poor families and those in rural areas - received no sex education at all.

The researchers found that teens who received comprehensive sex education were 60 percent less likely to get pregnant or to get someone pregnant than those who received no sex education.

Other results - not statistically significant, however - suggested that comprehensive sex education, but not abstinence-based sex education, slightly reduced the likelihood of teens having vaginal intercourse. Neither approach seemed to reduce the likelihood of reported cases of sexually transmitted diseases.

The findings, published in the April issue of theJournal of Adolescent Health, support comprehensive sex education, Kohler concluded.

"There was no evidence to suggest that abstinence-only education decreased the likelihood of ever having sex or getting pregnant," she said in a prepared statement.

This study offers "further compelling evidence" about the value of comprehensive sex education and the "ineffectiveness" of the abstinence-only approach, said Don Operario, a sex education expert and professor at Oxford University in England.

Source: www.washingtonpost.com

Calorie Count to Appear Soon on New York Menus

Did you hear that beginning March 31, all chain restaurants in New York City will have to prominently post calorie data on their menus?

Indeed, as noted here previously, the city's Board of Health voted unamimously last month to require this information in the hopes that it will help combat obesity, as CNN and CSPI pointed out.

About 54 percent of adults in New York City are overweight or obese.

The new regulation applies to restaurants with 15 or more outlets nationwide – or about 10% of all New York City restaurants.

This move has the backing of a number of health groups. In fact, the The Obesity Society just came on board to show support.

Not surprisingly, New York's restaurant lobby is against this requirement, and the group even filed a lawsuit suit last summer to stop it. (One of their arguments was that listing calories would make menus look too cluttered. Forgive me for smiling, but that strikes me as a somewhat ludicrous excuse.)

While it may be useful for New Yorkers - and people in other cities - to learn how many calories are in foods they're thinking of ordering, I think it would be useful to know sugar content, too.

As I've said previously, calories just don't tell the full picture.

But the big questions are these:

• Will this calorie information spur overweight or obese people to select options that are lower in calories?
• And if they're eating at a fast-food restaurant in the first place, do you really think weight loss is a big consideration for them?

It'll be interesting to see how this plays out. But don't look for me at fast-food restaurants to gauge the effectiveness of this new regulation. (I just don't hang out at those places.)

Source: www.commonvoice.com

Study Ffinds Long Term Heavy Use of Cell Phones Does Increase Cancer Risk

It's not uncommon that studies done on the same subject often come to vastly different conclusions; and studies on the link between increased risk of cancer and cell phone usage are no exception.

A study published last year in American Journal of Epidemiology has shown that frequent cell phone users face a 50 percent higher risk of developing certain types of tumors. Specifically the risk of developing parotid tumors is increased by 50 percent. The parotid is the largest salivary gland and is located near the jaw and ear where cell phones are typically held.

A 50 percent increased risk of cancer sounds very serious, and any increased chance of cancer should be taken seriously. However, if you stand back and look at the actual numbers the chance of getting a tumor from using a cell phone is still incredibly minute.

A study performed by Mark Kidd showed that in heavy cell phone users the risk of parotid tumors increased from 0.003 percent to 0.0045 percent.

In September of 2007 DailyTech reported that the Mobile Telecommunications and Health Research Programme published a study stating that there was no short-term link between cancer and cell phone use. The report did say that more research was needed into the association of long term cell phone use and cancer.

A study by Dr. Siegal Sadetzki showed that using a cell phone for more than 10 years does in fact raise the risk of brain cancer and notes that children are particularly at risk because of their developing skulls. Sadetzki says, “While I think this technology is here to stay, I believe precautions should be taken in order to diminish the exposure and lower the risk for health hazards.”

Sadetzki recommends using a hands-free device at all times and holding the phone away from the body along with shorter less frequent calls. She also says limit the time kids spend on the phone.

Source: www.DailyTech.com

Obesity Increases Cancer Risk, Analysis Of Hundreds Of Studies Shows

Researchers from the University of Manchester, Christie Hospital and University of Bern in Switzerland have today published findings in the Lancet medical journal which further support the link between obesity and risk of developing cancer.

Following on from findings reported by the World Cancer Research fund last year, the study reveals that risk is increased not only in common cancers such as breast, bowel and kidney, but also in less common cancers such as blood cancers (myeloma and leukaemia) and melanoma (a form of skin cancer).

Dr Andrew Renehan and colleagues from the University of Manchester and Christie Hospital, did a meta-analysis (a combined analysis of 221 previous studies), looking at over 250,000 cases of cancer, to determine the risk of cancer associated with a 5kg/m2 increase in body mass index (BMI).

The researchers found in men, a 5kg/m2 increase in BMI raised the risk of oesophageal adenocarcinoma by 52%, thyroid cancer by 33%, and colon and kidney cancers each by 24%.

In women, a BMI increase of 5kg/m2 increased the risk of endometrial (59%), gallbladder (59%), oesophageal adenocarcinoma (51%) and kidney (34%) cancers.

They also noted weaker, but significant, positive associations between increased BMI and rectal cancer and malignant melanoma in men; postmenopausal breast, pancreatic, thyroid, and colon cancers in women; and leukaemia, multiple myeloma, and non-Hodgkin's lymphoma in both sexes. They found associations were stronger in men than in women for colon cancer - 24% in men compared with 9% in women.

The study looked at cancer data from all over the world, and while the results for North America, Europe, Australia and the Asia-Pacific region were broadly similar, there was a stronger link between increased BMI and both premenopausal and post menopausal breast cancers in Asia-Pacific populations.

The senior author on the study, Dr Andrew Renehan, said: "This was a hugely comprehensive piece of research looking at 221 different studies in 20 types of cancer. For some cancer types, associations differ between sexes and populations of different ethnic origins and this should inform the exploration of biological mechanisms that link obesity with cancer."

He added: "Over the past five years, there was been increasing proof that obesity is linked with cancer risk, but despite this, we do not know whether weight reduction in people protects them against cancer. The findings of this study are important to address these issues and explore ways to prevent cancers in the future."

In an accompanying comment, Dr Susanna Larsson and Dr Alicja Wolk, Division of Nutritional Epidemiology, National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden, say: "The number of deaths per year attributable to obesity is about 30000 in the UK and ten times that in the USA, where obesity has been estimated to have overtaken smoking in 2005 as the main preventable cause of illness and premature death."

They conclude: "Efforts will be needed to increase education on diet and physical activity, train health professionals, restrict advertisements of high-calorie and low-nutrient foods, limit access to unhealthy foods in schools and workplaces, levy taxes on sugary drinks and other foods high in calories, fat, or sugar, lower the prices of health foods, and promote physical activity in schools and workplaces. National cancer plans should include all these factors to reduce obesity, and thus decrease cancer incidence and increase survival."

Source: www.sciencedaily.com

Many Prostate Cancers Will Not Need Treatment

One of the largest studies of its kind concludes that most older men with early prostate cancer do not shorten their survival odds if they adopt a "wait-and-see" approach to the disease.

In fact, most such patients will die of other causes or they simply won't develop any complications from the cancer, the researchers found.

"Many elderly men with lower risk cancer may do well with conservative management," concluded study author Grace Lu-Yau, a cancer epidemiologist at the Cancer Institute of New Jersey, and an associate professor at UMDNJ-Robert Wood Johnson Medical School and School of Public Health.

"Each patient facing a treatment decision has to ask himself what is the potential survival benefit of various treatments and the potential side effects of various treatments, then compare this potential risk of side effects with the potential risk of cancer complications if the cancer is left untreated - and ask themselves which treatment option is their personal preference," Lu-Yau said.

She presented the findings to reporters at a special teleconference Tuesday, part of the 2008 Genitourinary Cancers Symposium taking place in San Francisco.

The question of whether to treat or not treat prostate cancer has long absorbed experts.

Although one in six men in the United States will be diagnosed with prostate cancer in their lifetime, many of the malignancies are slow-growing, and there is currently no reliable way to identify which men will benefit from treatment. Better knowledge of the natural history of the disease (i.e., what happens without any treatment) would help guide treatment decisions, Lu-Yau said.

This study is one of the first to look at the natural history of prostate cancer since PSA (prostate-specific antigen) blood testing has become commonplace. PSA tests can detect a prostate cancer six to 13 years earlier than previous methods.

Lu-Yau and her colleagues looked at data on more than 9,000 men with Stage I or II prostate cancer diagnosed between 1992 and 2002 who did not undergo treatment. The mean age of participants was 77 years.

Seventy-two percent of these men died of other causes or didn't have enough cancer progression to warrant surgery or radiation, the researchers found. For the remaining 2,675 men who did receive treatment, the median time between diagnosis and start of therapy was more than 10 years.

Not surprisingly, men with less aggressive disease survived longer than those with more aggressive tumors.

"For elderly men with localized prostate cancer, the potential survival benefit for treatment is most likely modest, therefore it is very critical to weigh the risk of having side effects of various treatments with the risk of developing cancer-related complications down the road," Lu-Yau said. "The majority of patients will die of other causes or remain alive without significant major complications."

A second study presented at the conference found that giving salvage radiation therapy (SRT) to men whose PSA levels rise after having their prostate removed can reduce their risk of dying from the cancer by more than 60 percent.

SRT is typically given only after a recurrence, not after an initial diagnosis of prostate cancer, noted study lead author Dr. Bruce Trock, associate professor of urology, epidemiology, oncology and environmental health sciences at Johns Hopkins University School of Medicine in Baltimore. Existing studies have either not been large enough or long enough in duration to determine if SRT prolongs survival.

In this retrospective analysis of 635 men who had experienced a recurrence after having their prostate removed, 62 percent of those who did not receive any salvage therapy were still alive after 10 years, versus 86 percent of those who received SRT and 82 percent of those who received SRT plus hormone therapy.

Men whose PSA doubling time (the amount of time it took for PSA levels to double from when in first becomes detectable) was six months or less had the greatest benefit.

"If another study was able to replicate our data, it could lead to clinical trial that would eventually support a way to determine who should get immediate adjuvant radiation and who could wait until the time of recurrence to have SRT," Trock said. "The question is, could a benefit be achieved in some of these men if you waited to see whether they recurred or not?"

Source: www.washingtonpost.com

High Blood Pressure on Increase Among American Women

Uncontrolled hypertension rates are on the increase among American women, and the prevalence of this major risk factor for heart disease and stroke among American men is still not as low as it should be, a new survey shows.

"Blood pressure that is higher than optimal is among the leading two or three risks for cardiovascular disease, if not the leading one," said Majid Ezzati, an associate professor of international health at the Harvard School of Public Health and lead author of the report in the Feb. 12 issue of Circulation.

About one in five American adults has "uncontrolled high blood pressure," defined as a systolic pressure - the higher number of the 140/90 reading - above 140, according to the state-by-state survey. Data from two major ongoing studies, the National Health and Nutrition Examination Survey and the Behavioral Risk Factor Surveillance System, was used in the survey.

The incidence of uncontrolled high blood pressure had been declining steadily for decades into the 1990s, the researchers found. The decline has continued for American men, with the rate dropping from 19 percent to 17 percent in the early 2000s. But the incidence among American women increased from 17 percent to more than 22 percent during that same period.

There are big state-by-state differences, with the incidence of hypertension highest in southern states and the District of Columbia and lowest in Northeastern and Midwestern states such as Vermont, Connecticut, Minnesota, New Hampshire, Iowa and Colorado.

"We also found that in every state in the United States, women have higher uncontrolled hypertension prevalence rates than men do," Ezzati said in a statement. "The difference between men and women is as low as 4 percent and as high as 7 percent."

"We need to look nationally, but also especially focus on those states with the highest hypertension prevalence and emphasize interventions to do better than last decade's trends," Ezzati said.

The persistent incidence of hypertension is "principally a failure of our health-care delivery system," said Dr. Dan Jones, president of the American Heart Association. "Certainly physicians have some fault, patients have some fault, and biology plays a role. But in our current health-care system, high blood pressure is treated as part of a visit with a primary-care physician that may take only five to 15 minutes. It may be one of five or six problems that the patient has and may be the least symptomatic of those problems, so it doesn't get the attention it should."

Even when the problem is detected and hypertension medication is prescribed, "patients need to take the medicine on a regular basis, and simply fail to do so," Jones said.

Measures other than drug treatment can keep blood pressure under control, Ezzati added. "Lowering salt intake, including regulation in packaged and prepared foods, and regular testing should both be effective, as would, of course, more exercise and lower weight," he said.

"We've got to make hypertension a high priority in the treatment of patients," Jones said.

Source: www.forbes.com

Scientists Reprogram Human Skin Cells Into Embryonic Stem Cells

U.S. scientists say they've reprogrammed human skin cells into ones with the same blank-slate properties as embryonic stem cells, a breakthrough that could aid in treating many diseases while sidestepping controversy.

Human embryonic stem cells have the ability to become every cell type found in the human body. Being able to create these cells en masse and without using human eggs or embryos could generate a potentially limitless source of immune-compatible cells for tissue engineering and transplantation medicine, said the scientists, from the University of California, Los Angeles.

The researchers genetically altered human skin cells using four regulator genes, according to findings published online in the Feb. 11 edition of the journal Proceedings of the National Academy of the Sciences.

The result produced cells called induced pluripotent stem cells, or iPS cells, that are almost identical to human embryonic stem cells in function and biological structure. The reprogrammed cells also expressed the same genes and could be coaxed into giving rise to the same cell types as human embryonic stem cells, the researchers said.

"Our reprogrammed human skin cells were virtually indistinguishable from human embryonic stem cells," lead author Kathrin Plath, an assistant professor of biological chemistry and a researcher with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, said in a prepared statement. "Our findings are an important step towards manipulating differentiated human cells to generate an unlimited supply of patient specific pluripotent stem cells. We are very excited about the potential implications."

The UCLA findings confirm similar work first reported in late November by researcher Shinya Yamanaka at Kyoto University and James Thompson at the University of Wisconsin. Together, the studies demonstrate that human iPS cells can be easily created by different laboratories and are likely to mark a milestone in stem cell-based regenerative medicine, Plath said.

Reprogramming adult stem cells into embryonic stem cells has significant implications for disease treatment. A patient's skin cells, for example, could be reprogrammed into embryonic stem cells that could be prodded into becoming beta islet cells to treat diabetes, hematopoetic cells to create a new blood supply for a leukemia patient, or motor neuron cells to treat Parkinson's disease, the researchers said.

These new techniques to develop stem cells could potentially replace a controversial method to reprogram cells called somatic cell nuclear transfer (SCNT), sometimes referred to as therapeutic cloning. To date, therapeutic cloning has not been successful in humans.

"Reprogramming normal human cells into cells with identical properties to those in embryonic stem cells without SCNT may have important therapeutic ramifications and provide us with another valuable method to develop human stem cell lines," study first author William Lowry, an assistant professor of molecular, cell and developmental biology, said in a prepared statement. "It is important to remember that our research does not eliminate the need for embryo-based human embryonic stem cell research, but rather provides another avenue of worthwhile investigation."

However, top stem cell scientists worldwide stress further research comparing reprogrammed cells with stem cells derived from embryos - considered the gold standard - is necessary.

Source: www.forbes.com

Scientists create three-parent embryos

Sugar Substitutes May Contribute to Weight Gain

Surprising research suggests a popular artificial sweetener has the unexpected and unwelcome effect of packing on the pounds.

Purdue researchers report that saccharin altered the ability of rats to control their appetites. However, the head of an artificial sweetener trade group scoffed at the findings, saying they don't necessarily translate to humans.

"We found that the rats that were getting artificially sweetened yogurt gained more weight and ate more food," said study author Susan Swithers, an associate professor of psychological sciences at the Ingestive Behavior Research Institute at Purdue University. "The take-home message is that consumption of artificially sweetened products may interfere with an automatic process."

That process, she said, involves the body's ability to detect that it will soon be full. "We often will stop eating before we've been able to absorb all of the calories that come from a meal. One of the reasons we might stop eating is that our experience has taught in the past that, 'After I eat this food, I'll feel this full for this long,' " she explained.

It seems to be a subconscious process based on automatic estimations of how much energy certain foods will provide, she said. For example, a sweet taste might be a sign that "calories are coming, and I should prepare my body for the arrival of those calories." However, when the sweetness is not followed by a lot of calories, the body's digestive system gets confused, and the metabolism rate does not gear up as much the next time sweetness is tasted.

To test this theory, the researchers fed two different types of plain Dannon yogurt to male rats. Some received yogurt sweetened with glucose, a form of sugar, while others ate saccharin-sweetened yogurt. All also ate unsweetened yogurt.

The rats who ate artificially sweetened yogurt consumed more food overall and gained more weight. The body temperatures of those rats also didn't rise as high as the others. "That might be a kind of measure of energy expenditure, suggesting not only are the animals eating more calories, they may be expending or burning up fewer calories," Swithers said.

The findings were published in the February issue ofBehavioral Neuroscience.

Essentially, she said, it appears that the bodies of the rats are learning to not expect much in the way of calories from sweet foods. "The artificial sweetener provides the signal that not as many calories are going to come, and the animal responds by consuming more calories."

As for humans, she said, previous research has provided conflicting indications about whether obesity is a bigger problem among people who use artificial sweeteners.

According to her, launching a similar study among people would be difficult, because few have never encountered artificial sweeteners before. The next step, she said, is to do more research in rats.

Lyn Nabors, president of the Calorie Control Council trade group, lambasted the study, saying it has "no basis in science" and "no relation to the human experience whatsoever."

Artificial sweeteners can help people lose weight, she said. "The scientific community firmly believes that calories in, calories out is what makes a difference. The recommendation is that you reduce calories and exercise if you want to lose weight."

Source: www.washingtonpost.com

Pre-Chewed Baby Food Said to Transmit H.I.V.

Researchers have identified another way that babies can be infected with H.I.V. — through food pre-chewed by an infected parent or caretaker.

Although thousands of babies have been infected in the United States over the last 15 years, pre-chewed food has been documented as the cause of just three cases, federal epidemiologists said here Wednesday.

But such transmission may not be so rare, Dr. Kenneth L. Dominguez’s team from the Centers for Disease Control and Prevention said at the 15th Conference on Retroviruses and Opportunistic Infections.

Pre-chewing food apparently occurs among many groups in this country and elsewhere. So transmission of H.I.V., the AIDS virus, to infants may be an unrecognized problem in developing countries where dental care is lacking, commercially prepared baby foods and blenders are not available and parents and caretakers may need to soften foods, Dr. Dominguez said in an interview.

His team said there were several reasons for reporting the three cases, dating from 1993, for the first time. One was to make health care providers and caregivers of infected children aware of the potential risk of pre-chewing. Another was to ask doctors and family members to report suspected cases to health officials to quantify the threat.

Human immunodeficiency virus is present in saliva, but usually in amounts too low to cause transmission. So, presumably, blood, which has larger amounts of the virus, is also needed for transmission.

Infected chewers with inflammations or open mouth sores can pass the virus to infants through cuts or other common teething conditions, Dr. Dominguez said.

Although the three cases were among African-Americans born in the United States, pre-chewing is prevalent among many ethnic and racial groups, according to a recent national survey of infant feeding by the C.D.C., Dr. Dominguez said.

Specific findings from the survey have not been released.

“It’s likely that some cultural influences are involved, and I am sure that people are doing what their grandmothers and aunties did in practices carried through generations,” Dr. Dominguez said.

Epidemiologists from the centers, working with researchers at St. Jude Children’s Research Hospital in Memphis and the University of Miami, intensively investigated all three cases, ruling out other causes of transmission like breast feeding, sexual abuse and needle sticks.

The first two cases involved boys from Miami infected in the mid-’90s. One boy’s infection was detected when he was 39 months old, shortly before his death, after previously testing negative for the virus twice. The mother, who was infected, reported pre-chewing food for the boy.

The second boy’s mother was uninfected but lived with an infected aunt who pre-chewed his food. He survives. In the third case, a girl from Memphis was found to be infected in 2004 at 9 months old after testing negative for the virus three times. Her mother was infected and pre-chewed food for her daughter.

Genetic studies showed that the viruses isolated from the first and third cases matched those of the mother. The second case’s caregiver died before blood samples could be obtained. H.I.V. isolated from the caregiver’s infected male sexual partner did not match that from the boy.

Researchers will try to determine whether other dangerous microbes like hepatitis B virus and Helicobacter pylori might be transmitted through pre-chewed food.

Source: www.nytimes.com

Study: Cell Phone Use Affects Sperm Count, Quality

A recent study concluded that extended cell phone use may affect the number and quality of the male sperm count. This would significantly diminish a man's fertility, making it much harder to produce a baby.

Experts from a Cleveland Clinic explained that, according to their findings, the count and quality of produced male sperm is inversely proportional to the frequency of their use of the cell phone.

Measurements done from an experiment revealed that men who use their cell phones for four or more hours a day produced the lowest sperm count, as well as the least visible sperm, reported dbTechno.

Dr. Ashok Agarwal, the study's lead researcher, said that they noticed a "significant decrease in the most important measures of sperm health with cell phone use and that should definitely be reflected in a decrease in fertility."

Fox News said that the scientists are relating the decreased count and quality of sperm to the electromagnetic energy produced by the cell phones. They theorized that the energy was harming body tissue, particularly by harming the male's DNA.

The scientists, however, noted that their study did not directly point to the cell phones as the cause of sperm damage.

Source: www.allheadlinenews.com

Scientists Create Three-parent Embryos

British scientists have created human embryos with three parents in a development they hope could lead to effective treatments for a range of serious hereditary diseases within five years.

Researchers from Newcastle University, in northern England, presented their findings at a medical conference at the weekend, a university spokeswoman said on Tuesday.

The IVF, or test-tube, embryos were created using DNA from one man and two women.

The idea is to prevent women with faults in their mitochondrial DNA passing diseases on to their children. Around one in 5,000 children suffer from mitochondrial diseases, which can include fatal liver, heart and brain disorders, deafness, muscular problems and forms of epilepsy.

If all goes well, researchers believe they may be able to start offering the technique as a treatment in three to five years.

Mitochondria are tiny power packs inside cells that provide their energy. Faulty genetics can mean mitochondria do not completely burn food and oxygen, leading to the build-up of poisons responsible for more than 40 different diseases.

The Newcastle team believe these diseases could be avoided if embryos at risk were given an effective mitochondrial transplant. The process involves in vitro fertilization (IVF) and the subsequent removal of the egg's nucleus. The nucleus is then placed into a donor egg whose DNA has been removed.

The resulting fetus inherits nuclear DNA, or genes, from both parents but mitochondrial DNA from a third party.

"The idea is simply to swap the bad diseased mitochondria - give a transplant, if you like - for good healthy ones from a donor," Patrick Chinnery, a member of the Newcastle team, said in a telephone interview.

"We're trying to prevent kids being born with fatal diseases." Mitochondrial DNA is passed down only through the female line.

The technique has so far been tried only in the laboratory, using abnormal embryos left over from IVF therapy, and the handful of three-parent embryos created were destroyed after six days.

Stiff opposition to the technique is likely from critics of embryo research who fear the creation of designer babies.

The research was presented to the Medical Research Council Centre for Neuromuscular Diseases conference in London on February 1-2.

Source: www.reuters.com

Smokers Sleep Less Soundly

Smokers are four times more likely to feel tired when they wake up and they spend less time in deep sleep than nonsmokers do, a new study finds.

This may be because smokers experience nicotine withdrawal each night, which may contribute to sleep disturbances, suggest the study authors, whose report appears in the February issue ofChest.

"It is possible that smoking has time-dependent effects across the sleep period. Smokers commonly experience difficulty falling asleep due to the stimulating effects of nicotine. As night evolves, withdrawal from nicotine may further contribute to sleep disturbance," study author Dr. Naresh M. Punjabi, of Johns Hopkins University School of Medicine in Baltimore, said in a prepared statement.

Punjabi and colleagues studied the sleep patterns of 40 smokers and 40 nonsmokers. They found that 22.5 percent of smokers reported a lack of restful sleep, compared with only 5 percent of nonsmokers. Smokers also experienced a lower percentage of deep sleep and a higher percentage of light sleep.

The largest differences in sleep between the two groups occurred at the onset of sleep, which suggests the effects of nicotine are strongest in the early stages of sleep and decrease as the sleep cycle progresses, the researchers said.

These findings may help develop more effective ways to help people stop smoking.

"Many smokers have difficulty with smoking cessation partly because of the sleep disturbances as a result of nicotine withdrawal," Punjabi said. "By understanding the temporal effects of nicotine on sleep, we may be able to better tailor nicotine replacement to minimize the withdrawal effects that smokers experience, particularly during sleep."

Source: www.washingtonpost.com

A Daytime Nap Can Boost Memory

A 45-minute midday nap can help boost your memory and remember facts, but only if you learned them well in the first place, a new study suggests.

This type of memory is called "declarative memory" and applies to standard textbook learning and knowledge, in contrast to "procedural memory," which applies to skills. Sleep appears to help "set" these declarative memories and make them easier to recall, the researchers said.

"Sleep appears to have an impact on what is learned well, but not so much when one is not motivated to learn," said lead researcher Matthew A. Tucker, a postdoctoral fellow at Harvard Medical School's Center for Sleep and Cognition.

For the study, 33 people were trained with certain declarative memory tasks. After the training, 16 took a non-REM nap, while 17 stayed awake and watched a movie. Later the same day, all the participants were tested. The tests included memorizing words, memorizing a maze and memorizing a complex line drawing.

Tucker's team found that over three very different declarative memory tasks, taking a nap improved performance compared with staying awake. However, napping only worked for people who had really learned the task well in the first place.

"The nap group performed better overall than the awake group, but the difference wasn't significant," Tucker said. "However, when we looked at individual performance during training, we found those who did better during training benefited from napping," he said.

In addition, people appeared to perform well on one task only, but not all three, Tucker said. "There is likely a basic level of learning that has to be attained before sleep can have an impact on performance," he said.

The findings were published in the Feb. 1 issue of the journalSleep.

Tucker thinks that taking a nap may actually improve one's memory of facts if one is motivated to learn. "There is a lot of data starting to come in that there are benefits from naps on memory," he said.

Sara Mednick, an assistant professor at the University of California, San Diego's Laboratory of Sleep and Behavioral Neuroscience, said the new study is further proof of the role of sleep on memory and learning.

"This paper is further evidence of how sleep, specifically naps, can be a tool for memory consolidation," she said. "Interestingly, the data shows that not all subjects utilize sleep for consolidation to a similar extent."

Source: www.washingtonpost.com

Click Here to grow vegetables in your kitchen NOW

Exercise Really Can Make You Younger, Study Shows

The study suggests that 30 minutes of moderate exercise five times a week has significant benefits

People who take exercise are biologically younger - by up to nine years - than those who don’t.

This striking finding may explain why exercise reduces the risk of heart attacks, diabetes, cancer, and other degenerative diseases. It actually suggests that active adults have cells that are measurably “younger” than those of inactive ones.

A team from King’s College London looked at biological molecules called telomeres that act as a clock, measuring the passage of the years. Telomeres are the caps at the end of the chromosomes, designed like the tips of a shoelace to protect them from damage.

In youth, telomeres are long, but they get shorter as we age, leading to a growing risk of damage. In the new study published in Archives of Internal Medicine the King’s team, together with colleagues from New Jersey, have shown that active people have longer telomeres than inactive ones.

They used data from the Twin Research Unit at King’s College to compare identical and non-identical twins, whose average age was just under 50. The study included more than 2,400 volunteers - mostly women - with an age range from 18 to 81.

Professor Tim Spector and Dr Lynn Cherkas from King’s, and Professor Abraham Aviv of New Jersey Medical School, asked the volunteers to fill in questionnaires about the amount of exercise they had done in the previous year. They also established whether they were smokers, their body mass index (BMI), and their socioeconomic status.

They found there was a significant link between telomere length in the volunteers’ white blood cells and the amount of exercise they took. This remained significant when adjusted for smoking, BMI, and social class.

Because genes also influence telomere length, the team checked the results by looking at a smaller group of identical twins. These pairs shared the same genes, but differed in their levels of everyday activity.

This confirmed that the link between telomere length and activity is also found in identical twins - powerful evidence that there is more to it than genetics.

The actual difference between active and inactive people was quite large. Dr Cherkas said: “Overall, the difference in telomere length between the most active subjects and the inactive subjects corresponds to around nine years of ageing.”

The team concludes: “The US guidelines recommend that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits.

“Our results underscore the vital importance of these guidelines. They show that adults who partake in regular physical activity are biologically younger than sedentary individuals.”

Professor Spector said: “Our study, performed on a large cohort, indicates that differences in telomere length between active and inactive individuals cannot be explained by variations in genes, smoking, BMI and socioeconomic status.

“A sedentary lifestyle appears to have an effect on telomere dynamics – thus providing a powerful message that could be used by clinicians to promote the potentially anti-aging effect of regular exercise.’

In a commentary in the same journal, Dr Jack Guralnik of the US National Institute on Ageing, says the results are provocative, but that more research is needed to prove them true.

“Persons who exercise are different from sedentary persons in many ways, and although certain variables were adjusted for in this analysis, many additional factors could be responsible for the biological differences between active and sedentary persons” he writes.

“Nevertheless, this article serves as one of many pieces of evidence that telomere length might be targeted in studying ageing outcomes.

Source: www.timesonline.co.uk

Diuretics Best for Hypertension and Metabolic Syndrome

Diuretics appear to be as good or better than other blood pressure drugs for treating hypertension in patients with metabolic syndrome, especially black patients, according to a U.S. study.

People with hypertension and metabolic syndrome are at high risk for complications of cardiovascular disease.

Researchers at Case Western Reserve University and University Hospitals Cases Medical Center in Cleveland analyzed data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).

It included 42,418 people with hypertension and at least one other risk factor for cardiovascular disease who were randomly assigned to take either the diuretic chlorthalidone (15,255), the calcium channel blocker amlodipine besylate (9,048), the alpha-blocker doxazosin mesylate (9,061), or the ACE inhibitor lisinopril (9,054).

Each drug was used to start treatment, and other drugs were added if necessary to control blood pressure. The majority of patients were followed for an average of 4.9 years, but the alpha-blocker part of the trial was halted after an average of 3.2 years due to increased rates of cardiovascular disease.

Among the patients in the study, 23,077 met the criteria for metabolic syndrome, which is defined as hypertension plus at least two of the following factors: diabetes or pre-diabetes; a body-mass index (BMI) of at least 30; high triglyceride levels; or low levels of high-density lipoprotein ("good" cholesterol).

"No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (nonfatal myocardial infarction [heart attack] and fatal coronary heart disease)," the study authors wrote.

Among patients with metabolic syndrome, those taking the diuretic had a lower rate of heart failure than those taking the other three drugs. Patients who took the ACE inhibitor and the alpha-blocker also had an increased risk of combined cardiovascular disease.

"The lack of benefit of the agents with the most favorable metabolic profile [i.e., ACE inhibitors and alpha-blockers] was especially marked in black participants with metabolic syndrome," the researchers wrote.

"The magnitude of excess risk of end-stage renal [kidney] disease [70 percent], heart failure [49 percent] and stroke [37 percent] and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar high risk was noted for those randomized to the alpha-blocker versus the diuretic."

The researchers concluded that the findings "fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles."

Source: www.washingtonpost.com

Critical Things to Know about Your Cholesterol

How's your cholesterol? Here's a guess: If you're healthy, you probably have no idea. New surveys show women tend to be clueless about their risks of heart disease, especially when it comes to managing their cholesterol.

High cholesterol can lead to clogged coronary arteries, which can cause heart attack and stroke.

But this kind of ignorance is anything but bliss. The reason: The artery clogging that makes heart disease the Number One killer of women late in life begins much earlier - in your 20s, 30s, and 40s - and that's when your cholesterol numbers may be sounding alarms. So, are you ready to start paying attention? Here, the things all women need to know now.

1. High cholesterol is surprisingly common.

Researchers with the Framingham Heart Study recently delivered a nasty surprise: Nearly a quarter of women in the study who are in their early 30s have borderline-high levels of bad cholesterol, as do more than a third in their early 40s and more than half in their early 50s. A third of women in all three age groups have low levels of good cholesterol.

Bad cholesterol, also known as low-density lipoprotein, or LDL, contributes to heart disease by laying down artery-clogging plaque; good cholesterol, or high-density lipoprotein (HDL), helps clear it away. "The double whammy of high LDL and low HDL is particularly dangerous," says Framingham researcher Vasan Ramachandran, M.D., of the Boston University School of Medicine.

2. Your doctor may miss the problem.

Though women are better than men about seeing a doctor regularly, the care they receive isn't as good when it comes to preventing and treating cardiovascular disease, according to new studies. "Perhaps doctors still haven't gotten the message that women need to control cholesterol," says Chloe Bird, Ph.D., author of one of these studies and a senior sociologist at the nonprofit RAND Corporation. Bird found that doctors are less likely to monitor and control cholesterol in women than in men, even when the women are at super-high risk of heart attack.

Part of the problem, she says, may be that many women see only a gynecologist. This isn't to say that OB-GYNs can't be good primary care doctors, but you have to make sure the doc is willing to monitor your heart health, especially if you already have diabetes or a heart issue. That means she should order cholesterol checks as part of your regular blood work and discuss the results with you. What does "regular" mean?

3. Your numbers may trick you.

Many people misunderstand the roles of so-called good and bad cholesterols, according to cardiologist and lipidologist Pamela Morris, M.D., of the Medical University of South Carolina in Charleston. "What we've learned is that HDL and LDL are independent predictors of a woman's heart attack risk," she explains. "We see women with high HDLs having heart attacks when their LDL is also high, and we also see heart attacks in women with very low LDL but also low HDL."

What that means to you: It's important to keep track of both. A woman wants to keep her HDL above 60 (the level at which HDL helps prevent disease) and her LDL below 100. If your HDL drops below 50 or LDL rises above 160, you need to take immediate action. That may include an LDL-lowering drug such as a statin, and it definitely includes a commitment to a heart-healthy diet and lifestyle.

4. You may need an "inflammation" test.

The math used to estimate your heart disease risk is a little misleading. If your LDL rises above the danger line of 160 or your HDL drops below 50, the math says you have an elevated risk of a heart attack within 10 years. But that warning may actually underestimate your risks beyond 10 years, Morris says. So when she has a female patient with cholesterol numbers in the intermediate range - LDL above 130 or HDL under 60 - she often takes a close look at the woman's whole-body inflammation level.

You can't see this kind of inflammation, but it's actually an independent measure of heart attack risk. You measure it by adding a test for high-sensitivity C-reactive protein (hs-CRP) to the usual cholesterol blood work. CRP, essentially a body chemical, usually rises anytime your body becomes inflamed. And since artery clogging is associated with inflammation, high CRP is viewed as a marker for clogged arteries. That means your C-reactive protein levels may help you and your doctor decide how aggressively you need to control borderline-high-cholesterol levels with drugs, diet, and exercise.

5. These foods are your best friends.

Certain classes of food chemicals can actively and powerfully lower a person's bad cholesterol. Two - soluble fiber and phytosterols - have so much science behind them that they've become part of standard medical prescriptions for treating high cholesterol. But dietitian Janet Brill, Ph.D., R.D., author of "Cholesterol Down," also recommends regularly eating almonds, ground flaxseed, apples, soy protein, and olive oil. Preliminary research suggests they all have cholesterol-lowering powers. "Each one works in a slightly different way," Brill says. "So together, you get a synergy that can dramatically lower cholesterol."

Almonds and olive oil are high in monounsaturated fats, which are thought to blend with LDL molecules in a way that speeds LDL's clearance from the blood by the liver. Flax is high in both soluble fiber, which lowers LDL by absorbing cholesterol from both food and bile inside the intestines, and omega-3 fatty acids, which studies show have anti-inflammatory effects. Other foods especially high in soluble fiber include oat bran, oatmeal, and apples. (Soluble fiber is different from insoluble fiber, the kind found in whole-grain bread and bran cereal. That's good for you, too, but it won't affect your cholesterol.) Soy may mimic natural estrogens in their LDL-clearing effects. Phytosterols are the plant version of animal sterols (a.k.a. cholesterol) and lower LDL by competing with it for absorption into the body. They're found in supplements or phytosterol-enhanced margarine such as Benecol.

You don't need any of these foods if your LDL is low, but experts still recommend them for everyone. What about steak, eggs, and cheese? They sure won't help your cholesterol, because they all contain a lot of it. But it's more important to focus on foods that lower your numbers rather than simply avoiding the bad stuff, experts say.

6. Good cholesterol may have a bad side.

The higher your HDL, the better, right? That's been the current thinking, due to HDL's protective effect. But here's a surprise you may have read about in some news reports: Studies are showing that HDL may actually have harmful proteins capable of boosting heart disease risks. A test to determine whether your HDL has the harmful proteins may be available in a few years. In the meantime, if your HDL is lower than 60, it's still OK to raise it a little as long as you don't go overboard. How? Try getting a lot of omega-3s from fish or fish oil, exercising regularly, controlling your weight, and avoiding smoking.

7. Your heart loves long walks.

Walking 10 miles a week brings lasting improvements in your heart health, according to researchers at Duke University Medical Center. The funny thing is, if you jog those 10 miles, you won't get quite as much benefit. "Duration appears to be key," says Duke's Cris Slentz, Ph.D., an exercise physiologist. "Jogging or walking 10 miles both burned around 1,200 calories, but in our studies, one took about two hours and the other, three."

Longer stints of exercise, even moderate exercise, may burn more belly fat - the little rolls of skin near your navel and the fat deep inside your abdomen. The latter is linked to metabolic syndrome, a condition associated with a host of cardiovascular risk factors including low HDL, high blood pressure, and high triglycerides (a kind of blood fat that contributes to heart disease).

Should you aim for weight loss as well as long walks? If you're overweight, absolutely. But understand that shedding a few pounds will make only a small dent in your cholesterol. Canadian researchers recently found that overweight women who lost about 25 pounds - no easy task - saw their LDL drop about 10 percent and their HDL rise by the same amount.

Source: cnn.com

See also: Top 10 Tips for a Healthy Heart

Can Yogurt Really Boost Your Health?

One of the hottest food marketing trends these days involves adding live bacteria to dairy products as a way to boost health.
A lawsuit challenges the health claims of Activia,a probiotic yogurt.Dannon claims Activia can help regulate your digestive system.

Now lawyers have filed a class-action lawsuit against yogurt maker Dannon, one of the biggest sellers of “probiotic” yogurts, saying the claims of a health benefit dupe consumers. The company’s Activia and DanActive line of yogurt products contain live bacteria and claim to help regulate digestion and boost the immune system. The suit, filed in United States District Court in California, seeks redress for consumers who purchased the yogurt products based on what it says are “bogus claims.'’

“Deceptive advertising has enabled Dannon to sell hundreds of millions of dollars worth of ordinary yogurt at inflated prices to responsible, health- conscious consumers,” said Los Angeles attorney Timothy G. Blood, of the firm Coughlin Stoia Geller Rudman & Robbins.

In response, Dannon issued a statement saying it “stands by the claims of its products and the clinical studies which support them.'’

“All of Dannon’s claims for Activia and DanActive are completely supported by peer-reviewed science and are in accordance with all laws and regulations,'’ said the statement. “Dannon’s advertising has always been and will continue to be absolutely truthful, and Dannon will vigorously challenge this lawsuit.”

Probiotics are defined as live microorganisms that, in sufficient amounts, confer a health benefit on the host. A growing body of research links probiotics to relief of digestive tract complaints such as irritable bowel syndrome, yeast infections, and diarrhea that results from certain illnesses. The idea behind probiotics is to increase the amount of beneficial bacteria in people’s intestinal tracts as a way to aid digestion, boost the body’s natural defenses and fight off harmful bacteria that can cause health problems.

Although the scientific evidence shows that probiotics really can help, questions remain about how well that research translates into the real world, where some marketers may add untested amounts of the bacteria to various foods. While there are thousands of different probiotics, only a handful have been tested in clinical trials and been shown to deliver specific health benefits when eaten regularly. Most probiotic products can be found in the dairy case or as dietary supplements.

Dannon’s Activia line has been a marketing success story for the company, surpassing $100 million in sales in the United States its first year. The yogurt includes a form of Bifidobacteria that survives passage through the digestive tract, arriving in the colon as a living culture. The company claims that “once there, it plays a beneficial role in your intestinal ecosystem.'’ The yogurts are backed by a high-profile advertising campaign as well as a Web site. The site includes a link to company-sponsored studies showing that the bacteria used in Activia significantly improves regularity in study subjects.

The firm’s DanActive line, meanwhile, contains a different type of bacteria the company claims “helps strengthen your body’s defense.'’

The Food and Drug Administration doesn’t do much to guide consumers on the issue, simply policing food packages to make sure that companies do not try to equate probiotic products with disease-curing drugs.

A 2006 report from the American Society for Microbiology noted that “at present, the quality of probiotics available to consumers in food products around the world is unreliable.”

Source: well.blogs.nytimes.com

US Company Claims Cloned Humans, Made Stem Cells

A California company said on Thursday it used cloning technology to make five human embryos, with the eventual hope of making matched stem cells for patients. Stemagen Corp. in La Jolla, California, destroyed the embryos while testing to make sure they were true clones. But the researchers, based at a fertility center, said they believed their ready source of new human eggs would make their venture a success.

Other experts were skeptical about the claims, published in the journal Stem Cells. If verified, the team would be the first to prove they have cloned human beings as a source of stem cells, the master cells of the body.

There are several types of stem cells. Embryonic stem cells, made from days-old embryos, are considered the most powerful because they can give rise to all the cell types in the body.

The Stemagen team said they got five human embryos using skin cells from two adult men who work at the IVF center. They said they had painstakingly verified that the embryos were clones of the two men.

"We hope it is a bit of a turning point for many more studies," Andrew French, who led the research, said in a telephone interview.

They used a technique called somatic cell nuclear transfer, or SCNT, which involves hollowing out an egg cell and injecting the nucleus of a cell from the donor to be copied -- in this case, the skin cells from the men. It is the same technique used to make Dolly the sheep in 1996, the first mammal to be cloned from an adult. Researchers hope to use the technique to create tailor-made transplants of cells, tissue or organs for patients, treating injuries and diseases like juvenile diabetes.

"Since a significant percentage of couples undergoing fertility treatments appear willing to participate in this type of research, we believe the method described to obtain donated oocytes is a viable and ethically acceptable strategy," the researchers wrote.

MOST SUCCESSFUL SO FAR

Some cloning experts said the work appeared to be genuine.

"This is the most successful description so far of the use of the cloning techniques with purely human material. However, it is still a long way from achieving the goal of obtaining embryonic stem cells," said Robin Lovell-Badge of Britain's Medical Research Council's division of stem cell biology.

"I hope that the authors have the opportunity to continue their work and derive embryo stem cell lines," Ian Wilmut, who led the team that cloned Dolly and who is now at the University of Edinburgh, said in an e-mail.

The field is controversial for several reasons.

President George W. Bush opposes the use of human embryos to make stem cells and has vetoed bills from Congress that would expand federal funding of this research.

South Korean scientist Hwang Woo-suk made headlines when he was found to have faked key parts of a report that his team had used cloning technology to make human embryos in 2004.

"We need to be ultra-cautious after the Hwang scandal and not make the same mistake all over again," said Dr. Robert Lanza of Advanced Cell Technology, a Massachusetts company that is also trying to make human embryonic stem cells. "I'd really like to believe it, but I'm not sold yet," Lanza said.

Other teams have made stem cells they believe are similar to embryonic cells using a variety of techniques, including reprogramming a human egg cell alone, reprogramming ordinary skin cells into what are called induced pluripotent stem cells, or by taking one cell from a human embryo without harming the embryo.

But most stem cell experts agree it is important to continue trying to make stem cells from embryos too.

Source: www.reuters.com

Seawater Seems to Beat Medicine in Fighting Colds

There is no cure for the common cold, but researchers might have found a safe and simple way to reduce a child’s symptoms and the chance of recurrence: wash out the nose with seawater.

In a study published Monday in The Archives of Otolaryngology: Head and Neck Surgery, scientists assigned 289 cold or flu patients ages 6 to 10 to be given a nasal wash three times a day with water from the Atlantic Ocean that had been commercially processed but retained seawater’s trace elements and minerals.

As comparison, a group of 101 children used ordinary over-the-counter cough and cold medicines. Their symptoms were tracked over three months.

Patients on the saline treatment used fewer over-the-counter medicines, had fewer breathing problems and other cold symptoms, and reported fewer illnesses and school absences. The differences were statistically highly significant.

The authors acknowledge that the study was not blind and that the results depended in part on self-reporting by patients. The work was financed by Goemar Laboratoires, a French manufacturer of a saline solution based on seawater.

“It makes sense to clean the cavity where the microbes that might worsen the infection are present,” said Dr. Jana Skoupa', a co-author of the study, who works for a company that provides information to the pharmaceutical industry. “That’s what the seawater does, and it’s the minerals and trace elements in the seawater that help to restore the mucus lining of the nose.”

Source: www.nytimes.com

Quick Guide to Syphilis

8 Facts About Syphilis Everyone Should Know

New genetic evidence supports the theory that Christopher Columbus and his crew brought syphilis to Europe on the way back from their 1492 exploration of the Americas.

Following are facts about syphilis:

• Syphilis is a sexually transmitted disease caused by the the Treponema pallidum bacterium. Because its symptoms mimic those of other diseases, it is often called "the great imitator."
• Syphilis starts out with a painless sore at the site of infection, which often disappears without treatment.
• Weeks later, a rash appears that can cover any part of the body, including the palms of the hands and the soles of the feet. This may be accompanied by fever, fatigue and aches and pains. These signs appear and disappear for up to a year.
• In the tertiary stage, the bacteria may spread to internal organs including to the brain, causing numbness, paralysis, deafness and dementia. It may also cause heart trouble, including an inflammation of the aorta or heart valve problems.
• With early diagnosis, syphilis can be easily be treated with antibiotics.
• Before the advent of penicillin in the 1940s, syphilis had been treated in a range of uncomfortable ways, from toxic mercury to a risky practice of infecting victims with malaria in the hope that the fever would kill off the syphilis.
• Deborah Hayden, author of "Pox: Genius, Madness and the Mysteries of Syphilis," estimates that at its peak in the 19th century, syphilis may have infected as much as 15 percent of adults in Europe and North America.
• In a 2001 report, the World Health Organization estimated that there were an estimated 12 million cases of syphilis a year.

Source: www.reuters.com

Researchers Create Beating Heart With New Cells

Researchers at the University of Minnesota seeking new treatments for heart disease have grown a beating rat heart in the lab by using stem cells. VOA's Jessica Berman reports the research reported by the journal Nature Medicine is laying the groundwork for the transplant of what the scientists are calling bio-artificial organs in humans.

Experts say there are an estimated 100 million people around the world whose hearts do not work well enough to pump blood through their bodies. Many heart patients in need of a transplant will die waiting for a new organ to become available. But the researchers say if human hearts can be made from animal organs, they could save lives.

In their experiments, researchers removed the hearts of newborn lab rats and stripped them of their cells in a process called organ decellularization.

Lead researcher Doris Taylor, who heads the University of Minnesota's Center for Cardiovascular Repair, says investigators were left with a white protein matrix shaped like a heart that contained conduits where the blood vessels had been.

Dr. Taylor says these "ghost" hearts, or scaffolds, were re-populated by infusing them with progenitor cells that have a capacity for self-renewal and differentiation much like stem cells.

Within a few days, Dr. Taylor says the rat hearts began to grow cells on the outside.

"And what is really cool is that over time, our heart actually replaces that matrix that we call it," said Doris Taylor. "It is basically the cell saying 'I need something, something to hang on to,' and they build more of it over time. So, over time the human cells would replace that matrix and you would essentially have an equivalent of a human heart."

The new cells were fed nutrients and were prodded with a pacemaker. After four days, investigators noted some contractions in the rat hearts.

She says eight days later the experimental organs began pumping liquid faintly.

"What we were able to show is that we could take a previously dead heart that we removed all the cells from and really reanimate that with new cells," she said. "So, for the first time we have something that looks like a heart, that has the anatomy of a heart that we can actually begin to rebuild a whole tissue rather than just a little piece of tissue in a laboratory dish."

If perfected on larger hearts it could create a potentially unlimited supply of needed organs, and the researchers say use of a patient's own stem cells would ensure that a bio-artificial heart is compatible with his or her immune system.

The next step is to use the procedure on a pig heart to see if it will work in a larger heart.

Dr. Taylor says bio-artificial hearts for humans could be made from pig organs because the hearts are about the same size. Pig valves are already used to replace diseased heart valves in humans.

"The hope is that we have created a tool that will really make people think differently and provide an opportunity to create new options for tissue engineering and for patients who need organs," said Dr. Taylor.

Researchers in Minnesota are working with scientists in other countries to try to create other bio-artificial organs, including lungs, liver, the pancreas, and kidneys.

Source: www.voanews.com