Alcohol affects threat-detecting brain circuits

New brain imaging research published this week shows that, after consuming alcohol, social drinkers had decreased sensitivity in brain regions involved in detecting threats, and increased activity in brain regions involved in reward.

The study, in the April 30 issue of The Journal of Neuroscience, is the first human brain imaging study of alcohol's effect on the response of neuronal circuits to threatening stimuli.

"The key finding of this study is that after alcohol exposure, threat-detecting brain circuits can't tell the difference between a threatening and non-threatening social stimulus," said Marina Wolf, PhD, at Rosalind Franklin University of Medicine and Science, who was unaffiliated with the study. "At one end of the spectrum, less anxiety might enable us to approach a new person at a party. But at the other end of the spectrum, we may fail to avoid an argument or a fight. By showing that alcohol exerts this effect in normal volunteers by acting on specific brain circuits, these study results make it harder for someone to believe that risky decision-making after alcohol 'doesn't apply to me'," Wolf said.

Working with a dozen healthy participants who drink socially, research fellow Jodi Gilman, working with senior author Daniel Hommer, MD, at the National Institutes on Alcohol Abuse and Alcoholism, used functional magnetic resonance imaging (fMRI) to study activity in emotion-processing brain regions during alcohol exposure. Over two 45-minute periods, the study participants received either alcohol or a saline solution intravenously and were shown images of fearful facial expressions. (Previous studies have shown that expressions of fear signal a threatening situation and activate specific brain regions.)

The same group of participants received both alcohol and placebo, on two separate days.

Comparing brain activity, Gilman's team found that when participants received the placebo infusion, fearful facial expressions spurred greater activity than neutral expressions in the amygdala, insula, and parahippocampal gyrus-brain regions involved in fear and avoidance-as well as in the brain's visual system. However, these regions showed no increased brain activity when the participants were intoxicated.

In addition, alcohol activated striatal areas of the brain that are important components of the reward system. This confirms previous findings and supports the idea that activation of the brain's reward system is a common feature of all drugs of abuse. Gilman's team found that the level of striatal activation was associated with how intoxicated the participants reported feeling. These striatal responses help account for the stimulating and addictive properties of alcohol.

"I think the authors have set the standard for how studies on acute alcohol consumption should be conducted in the fMRI literature," says Read Montague, PhD, at the Baylor College of Medicine, also unaffiliated with the study. "The findings are a stepping stone to more liberal use of imaging methodologies to advance our understanding of addiction."

Since its development in 1993, fMRI has allowed the noninvasive mapping of function in various regions of the human brain. This technological advance is an important source of information for neuroscientists in a range of fields.

http://www.sfn.org/

Silver nanoparticles may kill beneficial bacteria

Too much of a good thing could be harmful to the environment. For years, scientists have known about silver's ability to kill harmful bacteria and, recently, have used this knowledge to create consumer products containing silver nanoparticles.

Now, a University of Missouri researcher has found that silver nanoparticles also may destroy benign bacteria that are used to remove ammonia from wastewater treatment systems. The study was funded by a grant from the National Science Foundation.

Several products containing silver nanoparticles already are on the market, including socks containing silver nanoparticles designed to inhibit odor-causing bacteria and high-tech, energy-efficient washing machines that disinfect clothes by generating the tiny particles. The positive effects of that technology may be overshadowed by the potential negative environmental impact.

"Because of the increasing use of silver nanoparticles in consumer products, the risk that this material will be released into sewage lines, wastewater treatment facilities, and, eventually, to rivers, streams and lakes is of concern," said Zhiqiang Hu, assistant professor of civil and environmental engineering in MU's College of Engineering. "We found that silver nanoparticles are extremely toxic. The nanoparticles destroy the benign species of bacteria that are used for wastewater treatment. It basically halts the reproduction activity of the good bacteria."

Hu said silver nanoparticles generate more unique chemicals, known as highly reactive oxygen species, than do larger forms of silver. These oxygen species chemicals likely inhibit bacterial growth. For example, the use of wastewater treatment "sludge" as land-application fertilizer is a common practice, according to Hu. If high levels of silver nanoparticles are present in the sludge, soil used to grow food crops may be harmed.

Hu is launching a second study to determine the levels at which the presence of silver nanoparticles become toxic. He will determine how silver nanoparticles affect wastewater treatment processes by introducing nanomaterial into wastewater and sludge. He will then measure microbial growth to determine the nanosilver levels that harm wastewater treatment and sludge digestion.

The Water Environment Research Foundation recently awarded Hu $150,000 to determine when silver nanoparticles start to impair wastewater treatment. Hu said nanoparticles in wastewater can be better managed and regulated. Work on the follow-up research should be completed by 2010.

http://www.missouri.edu/

High self-esteem not always what it's cracked up to be!

Oscar Levant, a mid-century pianist, film star and wit, once watched noted keyboardist and composer George Gershwin spend an evening playing his own music at a party and clearly having a great time.

"Tell me, George," Levant said, somewhat jealously, "if you have it to do all over again would you still fall in love with yourself""

Increasingly, psychologists are looking at such behavior and saying out loud what may go against the grain of how many people act: high self-esteem is not the same thing as healthy self-esteem. And new research by a psychology professor from the University of Georgia is adding another twist: those with "secure" high self-esteem are less likely to be verbally defensive than those who have "fragile" high self-esteem.

"There are many kinds of high self-esteem, and in this study we found that for those in which it is fragile and shallow it's no better than having low self-esteem," said Michael Kernis. "People with fragile high self-esteem compensate for their self-doubts by engaging in exaggerated tendencies to defend, protect and enhance their feelings of self-worth."

The research was published today in the Journal of Personality. Kernis's co-authors are Chad Lakey and Whitney Heppner, both doctoral students in the UGA social psychology program.

Amid the complexity of perspectives on the human psyche, a slow but relentless change is occurring in how psychologists view self-esteem, said Kernis. It was once thought that more self-esteem necessarily is better self-esteem. In recent years, however, high self-esteem per se has come under attack on several fronts, especially in areas such as aggressive behavior. Also, individuals with high self-esteem sometimes become very unlikable when others or events threaten their egos.

While high self-esteem is still generally valued as a good quality that is important to a happy and productive life, more researchers are breaking it down into finer gradations and starting to understand when high self-esteem turns from good to bad. In fact, it is now thought that there are multiple forms of high self-esteem, only some of which consistently relate to positive psychological functioning.

One of the ways in which high self-esteem can turn bad is when it is accompanied by verbal defensiveness-lashing out at others when a person's opinions, beliefs, statements or values are threatened. So Kernis and his colleagues designed a study, reported in the current article, to see if respondents whose self-esteem is "fragile" were more verbally defensive than those whose self-esteem was "secure."

Using 100 undergraduates, they set up a study in three phases. In the first part, students completed a basic demographic questionnaire and other measures to evaluate their levels and other aspects of self-esteem. In phase 2, the team assessed the students' stability of self-esteem because the more unstable or variable one's self-esteem, the more fragile it is. And finally, in the last phase, the researchers conducted a structured "life experiences interview" to measure what they call "defensive verbalization."

"Our findings offer strong support for a multi-component model of self-esteem that highlights the distinction between its fragile and secure forms," said Kernis. "Individuals with low self-esteem or fragile high self-esteem were more verbally defensive than individuals with secure high self-esteem. One reason for this is that potential threats are in fact more threatening to people with low or fragile high self-esteem than those with secure high self-esteem, and so they work harder to counteract them."

On the other hand, individuals with secure high self-esteem appear to accept themselves "warts and all," and, feeling less threatened, they are less likely to be defensive by blaming others or providing excuses when they speak about past transgressions or threatening experiences.

One reason the study's findings are important, Kernis said, is that it shows that greater verbal defensiveness relates to lower psychological well-being and life satisfaction.

"These findings support the view that heightened defensiveness reflects insecurity, fragility and less-than-optimal functioning rather than a healthy psychological outlook," said Kernis. "We aren't suggesting there's something wrong with people when they want to feel good about themselves. What we are saying is that when feeling good about themselves becomes a prime directive, for these people excessive defensiveness and self-promotion are likely to follow, the self-esteem is likely to be fragile rather than secure and any psychological benefits will be very limited."

And what of Oscar Levant and George Gershwin" While Levant may now be largely remembered for his acid opinions, Gershwin left us Rhapsody in Blue, An American in Paris, and Porgy and Bess, three of the most memorable compositions of the 20th century.

So the score for that fabled encounter on the secure self-esteem scale could be Gershwin 1, Levant, 0. Maybe it's a reminder of how complicated self-esteem really is.

http://www.uga.edu/

Daycare and play group attendance early on cuts childhood leukemia risk

Children who attend day care or play groups have about a 30% lower risk of developing the most common type of childhood leukaemia than those who do not, according to a new analysis of studies investigating the link.

The new research, to be presented Tuesday at the 2nd CHILDREN with LEUKAEMIA Causes and Prevention of Childhood Leukaemia Conference in London, is the first comprehensive analysis of studies investigating the association between social contact and childhood leukaemia.

"Combining the results from these studies together provided us with more confidence that the protective effect is real. Analysing the evidence in this way gives a more reliable answer to the question and a more precise estimate of the magnitude of the effect," said the study's leader, Dr. Patricia Buffler, professor of epidemiology at the School of Public Health of the University of California, Berkeley.

While the analysis does not reveal how intense social contact might ward off childhood leukaemia, it bolsters the theory that children exposed to common infections early in life gain protection from the disease. It is known that environments such as day care centres increase the chance of infections spreading. Some proponents of the theory believe that if the immune system is not challenged early in life and does not develop normally it may mount an inappropriate response to infections encountered later in childhood and that this could provoke the development of leukaemia.

Leukaemia is the most common cancer found in children in the industrialised world, affecting about one in 2,000 children. Incidence of the disease has been on the increase for decades. Acute lymphoblastic leukaemia, or ALL, the type of leukaemia the studies focused on, accounts for more than 80% of cases and most often occurs in children aged between 2 and 5 years. Scientists believe that for most types of childhood leukaemia to develop, there first must be a genetic mutation in the womb, followed by a second trigger during childhood that results in 1% of those children developing the disease. Infection - or the timing of infection - is one of the suspected triggers.

Buffler's analysis included 14 published studies comprising a total of 6,108 children with leukaemia and 13,704 without the disease. Parents were asked about day care and playgroup attendance, as well as other forms of social interaction with other children. The studies varied in the timing, duration and extent of social contact investigated and in the age groups and types of leukaemia studied. Twelve of the studies found some indication of a protective effect of social interaction with other children, while two found no effect. No study found that social contact increased the risk of childhood leukaemia.

"Our analysis concluded that children who attended day care or play groups had about a 30% lower risk of developing leukaemia than those who did not. Combined results for studies of day care attendance specifically before the age of 1 or 2 showed a similarly reduced risk," Buffler said.

The protective effect became even stronger when the researchers omitted from the analysis 5 studies in which the selection of healthy children for the comparison group relied on methods not considered optimal. In that analysis, children exposed to social contact were almost 40% less likely to go on to develop leukaemia than their counterparts.

In a separate report released at the conference on Tuesday by CHILDREN with LEUKAEMIA, scientists reviewed the evidence from studies that have investigated a link between infection and childhood leukaemia. They examined not only the idea that early life infections protect against the disease but also whether vaccination plays a role. In addition, they examined two other related areas of research: the role of infection during pregnancy and whether infection might be a factor influencing childhood leukaemia risk in situations where the population mix changes.

The report concluded that the evidence regarding whether infection during pregnancy or in situations of unusual patterns of population mixing influences the risk is inconclusive at present and that further research is necessary.

"On the question of whether infection early in life protects against leukaemia, the best evidence comes from studies of indirect measures of infection - which eliminates many of the problems common in trying to study infections directly - as well as from studies on immune system stimulation and on the genetics of immune responses," said one of the report's authors, Dr. Adrienne Morgan, staff scientist at CHILDREN with LEUKAEMIA.

"Putting our review together with the new analysis on social interaction, we can say pretty confidently that childcare, breastfeeding and vaccination are good things. This gives a steer to the biologists looking for what mechanisms might be at play," she said.

The 2nd CHILDREN with LEUKAEMIA Causes and Prevention of Childhood Leukaemia Conference will take place 29-30th April, 2008 at the Institute of Child Health, 30 Guilford Street, London WC1N 1EH. http://www.conferenceleukaemia.org/

http://www.leukaemia.org/

Thiazolidinediones may slow bone formation and speed bone loss

A widely used class of diabetes medications appears to be associated with an increased risk for fractures, according to a report in the April 28 issue of Archives of Internal Medicine.

"The insulin-sensitizing thiazolidinediones are a relatively new and effective class of oral antidiabetic agents that have gained wide use in clinical conditions characterized by insulin resistance," the authors write as background information in the article. Two drugs in this category, pioglitazone and rosiglitazone, account for 21 percent of oral diabetes medications prescribed in the United States and 5 percent of those in Europe. Recent studies have suggested that these therapies may have unfavorable effects on bone, resulting in slower bone formation and faster bone loss.

Christian Meier, M.D., of University Hospital Basel, Basel, Switzerland, and colleagues studied 1,020 patients with diabetes who had fractures diagnosed at British general practitioners' offices between 1994 and 2005. For each of those patients, up to four control patients with diabetes who were the same age and sex and had the same physician but did not have fractures were selected, for a total of 3,728 matched controls.

After adjusting for other risk factors, individuals who were currently taking rosiglitazone and pioglitazone had approximately double or triple the odds of hip and other non-spine fractures than those who did not take these drugs. The odds for fracture were increased among patients who took the drugs for approximately 12 to 18 months and the risk was highest for those with two or more years of therapy.

"This analysis provides further evidence of a possible association between long-term use of thiazolidinediones and fractures, particularly of the hip and wrist, in patients with diabetes mellitus," the authors conclude. "No such effect was seen for other antidiabetic drugs in this study population. These findings, although they are consistent with recently reported data from a randomized trial, are based on relatively few thiazolidinedione-exposed patients and need to be confirmed by additional observational studies and by controlled clinical trials."

http://archinte.ama-assn.org/

Wireless technology needed to build recession proof health services

Healthcare providers are increasingly using wireless technology to minimise the cost and disruption associated with the deployment of innovative ehealth and telecare services.

According to a report published this week by Cambridge UK based analysts, Wireless Healthcare, when healthcare providers are looking for technology that will reduce the cost of care, wireless is often the networking platform of choice.

The report, "Wireless Healthcare 2008", also identifies a number of consumer electronics companies that are seeking a safe harbour in the healthcare market as the recession impacts on their traditional markets. However, Wireless Healthcare warns that as a significant number of medical devices are purchased privately the healthcare market could also be adversely affected by the economic downturn. Peter Kruger, Analyst with Wireless Healthcare, points out, "Senior citizens, regarded as a key driver in the medical device market, sometimes fund their healthcare by withdrawing equity from their homes - something they will be unable to do when property values fall". Despite this, the report predicts continued growth in the market for fitness and wellbeing devices.

In Wireless Healthcare's last major study of the healthcare IT sector the lack of back office infrastructure, particularly electronic patient records (EPR), was highlighted as an inhibiter within the wireless medical device market. The latest report notes that some healthcare providers in the US and Europe have started to roll out EPR but sees incumbent providers facing increased competition from next generation healthcare providers who are deploying Health 2.0 based services.

"While there is a significant amount of hype regarding Health 2.0 a key component of this new healthcare concept, hosted patient records, will become increasingly important in driving demand for wireless ehealth services," states Kruger, who goes on to say, "We are seeing medical device vendors marketing products as 'Google Health ready' or building ehealth services using the Microsoft HealthVault SDK".

The report explains that while hosted patient records are a controversial issue within the healthcare sector they do provide the medical device developer with an alternative entry point into the healthcare market.

http://www.wirelesshealthcare.co.uk

Discovery of new way to prevent cardiac fibrosis

In a study that points to a new strategy for preventing or possibly reversing fibrosis - the scarring that can lead to organ and tissue damage - researchers at the University of California, San Diego School of Medicine have determined that a molecule called Epac (Exchange protein activated by cAMP1), plays a key role in integrating the body's pro- and anti-fibrotic response.

The research will be published in the online edition of the Proceedings of the National Academy of Science (PNAS) the week of April 21.

Inflammation is the body's response to injury in tissues, prompting healing that leads to scars, whether on the skin, or in organs such as the heart, liver or lungs. Such scarring has beneficial properties, but there's also the risk of excessive scarring, or tissue fibrosis, that can lead to organ damage and loss of function.

The UC San Diego researchers looked at cardiac fibrosis, which can occur in patients who have suffered an infection of the heart muscle or a heart attack. Such fibrosis causes the heart to stiffen so that it cannot adequately fill with blood and then empty itself, a condition known as diastolic dysfunction.

"An old heart is a stiff heart and some injured hearts are stiff as well," said Paul A. Insel, M.D., UCSD professor of pharmacology and medicine, and principal investigator of the study. "Much of the decrease in cardiovascular function that occurs with aging or, in some patients after a heart attack, can be explained by fibrosis. We wondered: What is responsible for excessive fibrosis" Is there a way to decrease or possibly reverse it"

It was previously known that a messenger molecule inside of cells, called cAMP, can block fibrosis in the heart. Insel and colleagues explored the mechanism leading to the anti-fibrotic effect, and discovered that the Epac molecule mediates cAMP actions that are involved in cardiac fibrosis. Epac also helps regulate other proteins that contribute to cell death, division, migration and motility.

"We found that Epac activation exerts a very important impact on the function of fibroblasts, the cells responsible for making and secreting collagen and thus for producing tissue fibrosis," said Insel. "Most exciting was our discovery that multiple agents that promote fibrosis decrease the expression and activation of Epac in fibroblasts from several different tissues - not only in the heart but also in lung, liver and skin."

The researchers found decreased Epac expression in regions near the site of heart attacks in rats and mice. In addition, they found that by increasing Epac expression, they were able to block the ability of agents to promote fibrosis.

Because increases in cAMP levels can decrease the function of fibroblasts after cell injury, stimulation of the cAMP signaling pathway is a potential way to blunt fibrosis. Increases in Epac expression may provide a novel way to do this, especially in cardiac fibroblasts, Insel added. To test this possibility, the scientists treated fibroblast cells in culture in ways that altered Epac expression, increasing Epac expression using an adenoviral construct.

"Using this strategy to overexpress Epac, we produced an anti-fibrotic effect, thereby inhibiting the synthesis of collagen" said Insel. "Other experiments showed that decreasing Epac expression favored fibrosis; in other words, were pro-fibrotic. Overall, the results show the central role of Epac in determining pro-fibrotic and anti-fibrotic response."

Additional contributors to the paper include Utako Yokoyama and Nakon Aroonsakool, UCSD Department of Pharmacology; Hemal H. Patel, David M. Roth, UCSD Department of Anesthesiology and Veterans Affairs San Diego Health Care System and N. Chin Lai, UCSD Department of Medicine and Veterans Affairs San Diego Healthcare System.

The study supported by grants from National Institutes of Health, the Ellison Medical Foundation and the American Heart Association.

http://www.ucsd.edu/

Naftidrofuryl for leg pain

Patients with pain caused by narrowed arteries in their legs have 37% more pain-free walking if they take naftidrofuryl (200mg three times a day) than those taking placebos, a Cochrane Review has found.

In addition, 55% of patients taking naftidrofuryl improved, while only 30% of people on placebo treatments improved. Naftidrofuryl is used to treat circulatory problems.

Cochrane Researchers came to this conclusion after identifying seven studies in which a total of 1266 patient had been treated for at least three months. They analysed the data by retrieving and pooling the original patient data.

The symptoms of intermittent claudication are pain, cramp or a sense of fatigue in leg muscles that increases on exercise such as walking, but goes away when the person rests. The condition affects less than 1% of people below the age of 49, but increases to over 5% of those aged 70 and older. The problem is that the arteries supplying the legs have hardened and narrowed due to fatty deposits. This makes it less easy for blood to carry oxygen and nutrients to the muscles or clear waste products away.

While stopping smoking and gently increasing exercise can reduce symptoms, interest has also been focused on some pharmaceutical products. Naftidrofuryl has been on the market since 1968 and has a good safety record. Its patent has expired, so there are many generic options in most countries.

"It would make sense to give naftidrofuryl alongside recommending lifestyle changes such as stopping smoking, physical exercise and also prescribing anti-platelet drugs and statins" says lead researcher Dr Tine de Backer who works at the Heymans Institute of Pharmacology in Gent, Belgium.

http://www.thecochranelibrary.com

Special asthma equipment a waste of money

Researchers from the Cochrane Collaboration research group have reviewed 54 studies in order to assess just how well specialist asthma equipment worked; the studies involved over 3,000 people.

According to experts many asthmatics are allergic to tiny mites that live in dust in carpets, bedding and soft toys - as a result a range of equipment such as mattress protectors, specialist cleaners, high-efficiency vacuum cleaners and air filters have appeared on the market to supposedly deal with the allergy.

The researchers say asthmatics should not waste money on such equipment as it is of little use, as they found while there was some dust mite reduction, it was not significant.

In 36 trials, physical methods, such as mattress casings, ten chemical methods, and eight methods which were a combination of chemical and physical methods were assessed.

While the team found that mite reduction occurred in 17 trials, it was judged not significant enough to help ward off asthma and the products were largely ineffective.

The researchers say the level of allergens is so high in most homes that what remains after the treatment is still high enough to cause asthma attacks.

Dr. Peter Gotzsche, the lead author of the review says he is confident that there is no need to buy expensive vacuum cleaners or mattress covers or to use chemical methods against house dust mites because these treatments do not work.

Experts say the study has confirmed other research which showed that dust prevention methods have little effect on reducing overall asthma symptoms.

There are currently 5.2 million people in the UK receiving treatment for asthma and over 2 million Australians have asthma.

Approximately 15% of Australian children have asthma and indigenous Australians have more problems with asthma than other Australians.

Even though asthma is one of the most common reasons for hospital admissions in children and around 400 people die each year from it, many asthma sufferers do not regularly use preventive medication.

Traditional dress protects ethnic girls from emotional problems

New research from Britain suggests that teenage girls from some minority communities who adhere to their family customs have better mental health.

The researchers from London's Queen Mary University, interviewed 1,000 white British and Bangladeshi teenagers and found that Bangladeshi girls who chose traditional rather than 'western' dress had fewer behavioural and emotional problems.

The researchers say close-knit families and communities helps to protect them even though the pressure to fully integrate fully could be stressful.

Co-author of the report Professor Kam Bhui says traditional clothing represents a tighter family unit, and this may offer some protection against some of the pressures that young people face.

The researchers say that adolescents are particularly vulnerable to mental health problems and their identity is often bound up in friendship choices or clothing, which plays a role.

The one thousand 11 to 14-year-olds were questioned about their culture, social life and health, including questions designed to reveal any emotional or mental problems.

The researchers found that the Bangladeshi students who wore traditional clothing were significantly less likely to have mental health problems than those whose style of dress was a mix of traditional and white British styles.

However when this was further broken down by gender, it appeared that only girls were affected and a similar effect was not found in white British adolescents who chose a mixture of clothes from their own and other cultures.

Professor Bhui says the results were a surprise because he had expected that girls who were less fully integrated to show signs of greater strain and he suggests that pressuring ethnic minority groups to integrate fully into a host society could be dangerous.

Professor Bhui says traditional clothing may reflect a protective environment, a traditional upbringing and religion, and religious coping mechanisms may be a part of their way of avoiding mental problems.

Professor Bhui has criticised countries who ban Muslim clothing such as headscarves.

The report is published in the Journal of Epidemiology and Community Health.

Health warning from Britain about vitamin supplements

Health authorities in Britain have issued a warning regarding Vitamin supplements, they say they are probably ineffective and are possibly harmful.

The advice from the Department of Health has been issued following a large review of scientific evidence published last year and advises caution over the use of Vitamin supplements.

Health officials say most people's nutritional needs are met by eating a balanced, varied diet including plenty of fruit and vegetables, and dietary supplements may do more harm than good.

The scientific review included 67 studies involving more than 230,000 people and has been republished by the Cochrane Collaboration, an international organisation for evidence-based research.

The review involved trials on beta-carotene, Vitamin A, Vitamin C, Vitamin E and selenium, with varying doses of each antioxidant.

The review found no evidence that the nutrition supplements extend life but found in fact that Vitamins A and E and beta carotene appear to slightly increase premature death rates among those taking them while Vitamin C and selenium have no effect.

The researchers say they found no evidence to support antioxidant supplements for primary or secondary prevention and beta-carotene, Vitamin A and Vitamin E given singly or combined with other antioxidant supplements significantly increase mortality.

The researchers say current evidence does not support the use of antioxidant supplements in the general healthy population or in patients with certain diseases.

They say more research on Vitamin C and selenium are needed and have called for more regulation of the health supplements industry and political action on the issue.

The Health Department says caution should be used in the use of high doses of purified supplements of Vitamins, including antioxidant Vitamins, and minerals, as their impact on long term health may not have been fully established and they cannot be assumed to be without risk.

Good sources of Vitamin A include cheese, eggs and oily fish; Vitamin E is found in foods such as soy, corn and olive oil; beta carotene is found in carrots, rockmelons, apricots and mangoes; Vitamin C is found in citrus fruits, strawberries, kiwifruit, capsicums, blackcurrants and potatoes; Selenium is found in meat, fish, shellfish, cheese and avocados.

Housework boosts mental health

Just 20 minutes of any physical activity, including housework, in a week is enough to boost mental health, reveals a large study published ahead of print in the British Journal of Sports Medicine.

While regular exercise is known to be good for mental health, no one seems able to agree on how much, or what type of activity, is best.

The findings are based on a representative sample of almost 20,000 men and women who were quizzed for the Scottish Health Survey about their state of mind and how much weekly physical activity they engaged in.

Over 3000 participants were deemed to be suffering from stress or anxiety, using a validated scoring system.

But any form of daily physical activity was associated with a lower risk of distress, when other influential factors, such as age, gender, and the presence of a long term condition, were taken into account.

The range of activities, which proved beneficial, included housework, gardening, walking, and sports, although the strongest effect was seen for sports, which lowered the risk of distress by 33%.

The results also indicated that while just 20 minutes improved mental state, the more activity a person indulged in, the lower were their chances of psychological distress.

Physical activity curbs the risks of a range of serious diseases, such as heart disease and certain cancers.

And it improves several biological risk factors, such as glucose intolerance and inflammation, which have themselves been linked to depression and dementia, say the authors.

http://www.bma.org.uk

Hepatitis B virus triggers cell 'suicide' in patients with chronic infection

Scientists from UCL (University College London) have identified a key difference between people who can fight the Hepatitis B virus (HBV) off successfully and those who fail to do so - that a group of cells important in controlling the disease are triggered to 'commit suicide' in patients who are chronically infected.

This discovery provides an important new focus for developing therapies or vaccines that boost the body's ability to manage this infection.

The researchers analysed thousands of genes in T cells, critical players of the immune system required for control of HBV. They found that T cells from patients who were chronically infected were triggered to 'commit suicide'. This could be an important factor in determining why these patients' immune systems cannot fight the infection, and a process which could be a useful target for new treatments. Their findings are published today in the Journal of Clinical Investigation.

Hepatitis B virus (HBV) is one of the most common viruses in the world, and ranks as one of the top ten killer infectious diseases. More than 350 million people have long-term infection with HBV, which may lead to liver cirrhosis, liver failure or liver cancer. In the majority of adults infected, the immune system is able to control the virus very well and is, in fact, more effective than any currently available treatment. Understanding what goes wrong in people with chronic infection is crucial to the development of new therapies.

Lead author, Dr Mala Maini, UCL Division of Infection & Immunity, said: "We used microarray gene chips to screen more than 5,000 genes in T cells from both recovered and chronically infected Hepatitis B patients. This led to the discovery that, instead of successfully reacting to the virus, the T cells in the latter group were triggered to commit suicide by one of the cells' own death-inducing proteins, called 'Bim'. We are now looking into the fine mechanism driving this outcome."

The paper's first author, Ross Lopes, added: "If we can develop safe ways of blocking the suicidal tendency of the T cells, we may be able to prolong their survival, so they can do a better job of controlling Hepatitis B infection."

The proportion of the world's population currently infected with HBV is estimated at between 3 and 6 per cent, but up to a third have been exposed. It is endemic in parts of Asia and Africa. Chronic Hepatitis B may eventually cause liver cirrhosis and liver cancer, a fatal disease with very poor response to current treatments. The infection is preventable by vaccination at a young age.

http://www.ucl.ac.uk/

Too little sleep and too much TV makes infants overweight

New research has found that infants and toddlers who sleep less than 12 hours a day are twice as likely to become overweight by age 3 than children who sleep longer.

This factor combined with watching too much of television elevates the risk even further.

The scientists from Harvard Medical School say children who sleep less than 12 hours and who watch two or more hours of television each day have a 16 percent chance of becoming overweight by age 3.

Dr. Elsie Taveras, an assistant professor at Harvard's Department of Ambulatory Care and Prevention says mounting research suggests that decreased sleep time may be more hazardous to our health than first imagined and such hazardous effects are true even for young infants.

Dr. Taveras is the lead author of a long-term study of the effects of diet and other lifestyle factors on maternal and child health called Project Viva.

The researchers identified 915 mother-infant pairs from Project Viva, and recorded infant weight and measurements at a number of personal visits.

The mothers were asked to record how many hours their child slept each day on average at 6 months, 1 year, and 2 years and to report the average number of hours their children watched television on weekdays and weekends.

The research team found that the combination of low levels of sleep and high levels of television viewing appeared to be synergistic and was associated with significantly higher BMI scores and an increased risk of becoming overweight.

Watching too much television viewing is a known risk factor for children becoming overweight, and a similar link has been found between sleep restriction and overweight in older children, adolescents and adults.

Previous research with adults, adolescents and older children has shown that restricting sleep changes hormone levels, which could stimulate hunger and increase weight gain.

However the study's senior author Dr. Matthew Gillman says this the first study to examine the connection in very young children.

Dr. Taveras says the presence of TV, Internet, and video games in the rooms where children sleep means getting enough sleep is becoming more and more difficult for children to achieve.

She suggests parents can improve children's' sleep quality and duration by removing TV from their children's bedrooms.

The study findings provide further evidence that reducing television viewing to promote adequate sleep will prevent and reduce unhealthy childhood weight-gain.

Children who are overweight are later in life more prone to obesity and related conditions, such as hyperlipidemia, hypertension, asthma, and type II diabetes.

The research was supported by funds from the National Institutes of Health, the Harold Amos Medical Faculty Development Program, and the Robert Wood Johnson Foundation.

The research is published in the current issue of Archives of Pediatrics & Adolescent Medicine.

Depression and Alzheimer's

People who have had depression are more likely to develop Alzheimer's disease than people who have never had depression, according to a study published in the April 8, 2008, issue of Neurology, the medical journal of the American Academy of Neurology.

The study involved 486 people age 60 to 90 who had no dementia. Of those, 134 people had experienced at least one episode of depression that prompted them to seek medical advice.

The participants were followed for an average of six years. During that time 33 people developed Alzheimer's disease. People who had experienced depression were 2.5 times more likely to develop Alzheimer's disease than people who had never had depression. The risk was even higher for those whose depression occurred before the age of 60; they were nearly four times more likely to develop Alzheimer's than those with no depression.

"We don't know yet whether depression contributes to the development of Alzheimer's disease or whether another unknown factor causes both depression and dementia," said study author Monique M.B. Breteler, MD, PhD, with the Erasmus University Medical Center in Rotterdam, the Netherlands. "We'll need to do more studies to understand the relationship between depression and dementia."

One theory was that depression leads to loss of cells in two areas of the brain, the hippocampus and the amygdala, which then contributes to Alzheimer's disease. But this study found no difference in the size of these two brain areas between people with depression and people who had never had depression.

The study also assessed whether the participants had symptoms of depression at the start of the study. But those with depressive symptoms at the start of the study were not more likely to develop Alzheimer's than those with no depression at the start of the study.

http://www.aan.com/

Heart transplant recipient repeats suicide act of donor

In a bizarre turn of events a man given the heart of suicide victim has now committed suicide in the same manner; even more bizarre is that he had been married to the donor's widow for over a decade.

The man, Sonny Graham, had been twelve years ago at death's door because of congestive heart failure.

He was given the heart of suicide victim Terry Cottle and later went on to marry his widow.

Mr Graham started corresponding with Mrs Cheryl Cottle, a mother of four, following the operation after being told her husband was his heart donor.

Twelve years after the successful transplant operation, 69 year old Graham shot himself dead, leaving the woman a widow for the second time in circumstances which bear a sinister similarity.

The woman now Mrs Graham, is a nurse living in Georgia, in the U.S. and is said to be devastated; Mr Graham, 69, died after shooting himself in the throat with a shotgun and was found in a garage at the home the couple shared.

Mr Cottle, 33 had committed suicide by shooting himself in the head.

Friends of the couple say Mr Graham had not shown any signs of being depressed.

Scientists say there are more than 70 documented cases of transplant patients having personality changes as they take on some of the characteristics of the donor which are known as cellular memory phenomenon.

Medical experts however are skeptical about the concept and say there is little convincing evidence to support such a phenomena.

Climate change and human health

Scientists tell us that the evidence the Earth is warming is "unequivocal." Increases in global average air and sea temperature, ice melting and rising global sea levels all help us understand and prepare for the coming challenges.

In addition to these observed changes, climate-sensitive impacts on human health are occurring today. They are attacking the pillars of public health. And they are providing a glimpse of the challenges public health will have to confront on a large scale, WHO Director-General Dr Margaret Chan warned today on the occasion of World Health Day.

"The core concern is succinctly stated: climate change endangers human health," said Dr Chan. "The warming of the planet will be gradual, but the effects of extreme weather events -- more storms, floods, droughts and heat waves -- will be abrupt and acutely felt. Both trends can affect some of the most fundamental determinants of health: air, water, food, shelter and freedom from disease."

Human beings are already exposed to the effects of climate-sensitive diseases and these diseases today kill millions. They include malnutrition, which causes over 3.5 million deaths per year, diarrhoeal diseases, which kill over 1.8 million, and malaria, which kills almost 1 million.

Examples already provide us with images of the future:European heat wave, 2003: Estimates suggest that approximately 70 000 more people died in that summer than would have been expected.

• Rift Valley fever in Africa: Major outbreaks are usually associated with rains, which are expected to become more frequent as the climate changes.
• Hurricane Katrina, 2005: More than 1 800 people died and thousands more were displaced. Additionally, health facilities throughout the region were destroyed critically affecting health infrastructure.
• Malaria in the East African highlands: In the last 30 years, warmer temperatures have also created more favourable conditions for mosquito populations in the region and therefore for transmission of malaria.
• Epidemics of cholera in Bangladesh: They are closely linked to flooding and unsafe water.

These trends and events cannot be attributed solely to climate change but they are the types of challenges we expect to become more frequent and intense with climate changes. They will further strain health resources that, in many regions, are already under severe stress.

"Although climate change is a global phenomenon, its consequences will not be evenly distributed," said Dr Chan. "In short, climate change can affect problems that are already huge, largely concentrated in the developing world, and difficult to control."

To address the health effects of climate change, WHO is coordinating and supporting research and assessment on the most effective measures to protect health from climate change, particularly for vulnerable populations such as women and children in developing countries, and is advising Member States on the necessary adaptive changes to their health systems to protect their populations.

WHO and its partners -- including the UN Environment Programme, the Food and Agriculture Organization, and the UN World Meteorological Organization -- are devising a workplan and research agenda to get better estimates of the scale and nature of health vulnerability and to identify strategies and tools for health protection. WHO recognizes the urgent need to support countries in devising ways to cope. Better systems for surveillance and forecasting, and stronger basic health services, can offer health protection. WHO will be working closely with its Member States in coming years to develop effective means of adapting to a changing climate and reducing its effects on human health.

"Through its own actions and its support to Member States," said Dr Chan, "WHO is committed to do everything it can to ensure all is done to protect human health from climate change."

http://www.who.int

Stress may lead students to stimulants

The performance pressures from end-of-semester exams and papers can take a toll on students, even leading them to turn to potentially harmful substances to keep them awake and alert.

Recent studies show that a growing number of high school and college students are turning to stimulants like ADHD (Attention Deficit Hyperactivity Disorder) drugs and energy drinks to help them through their stress - particularly during exam time, says Jennifer Christner, M.D., an adolescent medicine specialist at the University of Michigan Health System.

"Studies have shown that anywhere from 5 to 35 percent of college students are misusing stimulants around stressful times with academics. There is also some evidence that high school students - anywhere from 8 to 10 percent - can misuse stimulants during these times," she says.

Approximately 25 percent of high school and grade school children have been approached by friends to use their medication, Christner notes. This causes children to be more susceptible to misusing medications that are not prescribed to them, a decision that can be damaging to their health.

"It is never a good idea to use anyone else's medication, whether it is a prescribed medication or over-the-counter," she says. "Of course, if you have ADHD, then use your stimulant on a regular basis and not just when you really need it at crunch-time."

Misuse of stimulants can lead to depression, irritability, stomachaches and headaches. Serious misuse or abuse of these drugs can lead to very serious side effects, including hypertension and stroke.

The growing popularity of energy drinks can also be harmful to a child's health, Christner adds.

"There is harm when someone is taking more than one or two of these drinks a day," she says. "The caffeine can lead to jitteriness, anxiety, increased heart rate and the more serious side effects of high blood pressure, hyperthermia and stroke."

While Christner notes that drinking one energy drink during a demanding time is usually acceptable, there are ways that a person can maintain energy levels and avoid stimulants altogether. To help ease academic anxiety, she recommends that students do their work steadily, as opposed to saving it all for the last minute. She also suggests keeping up with regular exercise, eating a balanced diet and getting proper rest.

Concerned parents can also take steps toward preventing their children from overusing stimulants, Christner says. Parents can role play with their children and ask them what they would say and do if they were offered medications from their friends. Parents can also be conscientious during the time of their college-aged children's exams simply by calling and asking if their son or daughter is doing okay.

Christner also advises family members to look out depression, irritability and other warning signs of stimulant abuse.

http://www.umich.edu

Optimal level of anxiety

Anxiety gets a lot of bad press. Dwelling on the negative can lead to chronic stress and anxiety disorders and phobias, but evolutionarily speaking, anxiety holds some functional value.

In humans, learning to avoid harm is necessary not only for surviving in the face of basic threats (such as predators or rotten food), but also for avoiding more complex social or economic threats (such as enemies or questionable investments).

A team of psychologists at Stanford University have identified a region of the brain, the anterior insula, which plays a key role in predicting harm and also learning to avoid it. In a new study, Gregory Samanez-Larkin and colleagues scanned the brains of healthy adults while they anticipated losing money.

Adults with greater activation of their insula while anticipating a financial loss were better at learning to avoid financial losses in a separate game several months later. Conversely, participants with low levels of insula activation had a harder time learning to avoid losses and lost more money in the game as a result.

For these subjects, higher levels of insula activation helped them to learn to avoid losses months later. However, researchers have found that excessive insula activation might prove problematic. Previous research has shown that people who are chronically fearful and anxious have abnormal patterns of insula activation. So, while people with excessive insula activity are at risk for psychological disorders like anxiety and phobias, higher levels of insula activation in the normal range may allow people to avoid potentially harmful situations.

The findings, which appear in the April issue of Psychological Science, a journal of the Association for Psychological Science, point toward an optimal level of anxiety. While a healthy amount of anxiety grants some survival value, too much may lead to excessive worry and clinical conditions. This may help to explain why anxious traits persist in humanity's genetic endowment, even as environmental threats vary over the ages.

http://www.psychologicalscience.org/

A daily dose of caffeine may help protect against Alzheimer's

A daily dose of caffeine blocks the disruptive effects of high cholesterol that scientists have linked to Alzheimer's disease.

A study in the open access publication, Journal of Neuroinflammation revealed that caffeine equivalent to just one cup of coffee a day could protect the blood-brain barrier (BBB) from damage that occurred with a high-fat diet.

The BBB protects the central nervous system from the rest of the body's circulation, providing the brain with its own regulated microenvironment. Previous studies have shown that high levels of cholesterol break down the BBB which can then no longer protect the central nervous system from the damage caused by blood borne contamination. BBB leakage occurs in a variety of neurological disorders such as Alzheimer's disease.

In this study, researchers from the University of North Dakota School of Medicine and Health Sciences gave rabbits 3 mg caffeine each day - the equivalent of a daily cup of coffee for an average-sized person. The rabbits were fed a cholesterol-enriched diet during this time.

After 12 weeks a number of laboratory tests showed that the BBB was significantly more intact in rabbits receiving a daily dose of caffeine.

"Caffeine appears to block several of the disruptive effects of cholesterol that make the blood-brain barrier leaky," says Jonathan Geiger, University of North Dakota School of Medicine and Health Sciences. "High levels of cholesterol are a risk factor for Alzheimer's disease, perhaps by compromising the protective nature of the blood-brain barrier. For the first time we have shown that chronic ingestion of caffeine protects the BBB from cholesterol-induced leakage."

Caffeine appears to protect BBB breakdown by maintaining the expression levels of tight junction proteins. These proteins bind the cells of the BBB tightly to each other to stop unwanted molecules crossing into the central nervous system.

The findings confirm and extend results from other studies showing that caffeine intake protects against memory loss in aging and in Alzheimer's disease.

"Caffeine is a safe and readily available drug and its ability to stabilise the blood-brain barrier means it could have an important part to play in therapies against neurological disorders," says Geiger.

http://www.biomedcentral.com/

Do humans hear better than animals?

It is known that various species of land and water-based living creatures are capable of hearing some lower and higher frequencies than humans are capable of detecting.

However, scientists from the Hebrew University of Jerusalem and elsewhere have now for the first time demonstrated how the reactions of single neurons give humans the capability of detecting fine differences in frequencies better than animals.

They did this by utilizing a technique for recording the activity of single neurons in the auditory cortex while subjects were exposed to sound stimuli. The auditory cortex has a central role in the perception of sounds by the brain.

Current knowledge on the auditory cortex was largely based on earlier studies that traced neural activity in animals while they were exposed to sounds. And while such studies have supplied invaluable information regarding sound processing in the auditory system, they could not shed light on the human auditory system's own distinctive attributes.

Experimental study of neural activity in the human auditory cortex has been limited until now to non-invasive techniques that gave only a crude picture of how the brain responds to sounds. But recently, investigators from the Hebrew University, the University of California, Los Angeles (UCLA), the Tel Aviv Sourasky Medical Center and the Weizmann Institute of Science were successful in recording activity of single neurons in the auditory cortex while the subjects were presented with auditory stimuli. They did this by utilizing an opportunity provided during an innovative and complicated clinical procedure, which traces abnormal neural activity in order to improve the success of surgical treatment of intractable epilepsy,

The researchers included Prof. Israel Nelken of the Department of Neurobiology at the Alexander Silberman Institute of Life Sciences at the Hebrew University of Jerusalem, Prof. Itzhak Fried from UCLA and Tel Aviv Medical Center, and Prof. Rafi Malach of the Weizmann Institute of Science, together with their students Roy Mukamel and Yael Bitterman. Their work was described in an article appearing in the journal Nature.

In tests measuring response to artificial sounds, the researchers found that neurons in the human auditory cortex responded to specific frequencies with unexpected precision. Frequency differences as small as a quarter of a tone (in western music, the smallest interval is half a tone) could be reliably detected from individual responses of single neurons.

Such resolution exceeds that typically found in the auditory cortex of other mammalian species (besides, perhaps, bats, which make unique use of their auditory system), serving as a possible correlate of the finding that the human auditory system can discriminate between frequencies better than animals. The result suggests that the neural representation of frequency in the human brain has unique features.

Interestingly, when the patients in the study were presented with "real-world" sounds - including dialogues, music (from "The Good, the Bad and the Ugly" soundtrack) and background noise - the neurons exhibited complex activity patterns which could not be explained based solely on the frequency selectivity of the same neurons. This phenomenon has been shown in animal studies but never before in humans.

Thus, it can be seen that in contrast to the artificial sounds, behaviorally relevant sounds such as speech and music engage additional, context-dependant processing mechanisms in the human auditory cortex.

http://www.huji.ac.il/

Fasting for two days protects healthy cells against chemotherapy

Fasting for two days protects healthy cells against chemotherapy, according to a study appearing online the week of Mar. 31 in PNAS Early Edition.

Mice given a high dose of chemotherapy after fasting continued to thrive. The same dose killed half the normally fed mice and caused lasting weight and energy loss in the survivors.

The chemotherapy worked as intended on cancer, extending the lifespan of mice injected with aggressive human tumors, reported a group led by Valter Longo of the University of Southern California.

Test tube experiments with human cells confirmed the differential resistance of normal and cancer cells to chemotherapy after a short period of starvation.

Making chemotherapy more selective has been a top cancer research goal for decades. Oncologists could control cancers much better, and even cure some, if chemotherapy were not so toxic to the rest of the body.

Experts described the study as one of a kind.

"This is a very important paper. It defines a novel concept in cancer biology," said cancer researcher Pinchas Cohen, professor and chief of pediatric endocrinology at the University of California, Los Angeles.

"In theory, it opens up new treatment approaches that will allow higher doses of chemotherapy. It's a direction that's worth pursuing in clinical trials in humans."

Felipe Sierra, director of the Biology of Aging Program at the National Institute on Aging, said: "This is not just one more anti-cancer treatment that attacks the cancer cells. To me, that's an important conceptual difference."

Sierra was referring to decades of efforts by thousands of researchers working on "targeted delivery" of drugs to cancer cells. Study leader Longo focused instead on protecting all the other cells.

Sierra added that progress in cancer care has made patients more resilient and able to tolerate fasting, should clinical trials confirm its usefulness.

"We have passed the stage where patients arrive at the clinic in an emaciated state. Not eating for two days is not the end of the world," Sierra said.

"This could have applicability in maybe a majority of patients," said David Quinn, a practicing oncologist and medical director of USC Norris Hospital and Clinics. He predicted that many oncology groups would be eager to test the Longo group's findings, and advised patients to look for a clinical trial near home.

Longo, an anti-aging researcher who holds joint appointments in gerontology and biological sciences at USC, said that the idea of protecting healthy cells from chemotherapy may have seemed impractical to cancer researchers, because the body has many different cells that respond differently to many drugs.

"It was almost like an idea that was not even worth pursuing. In fact it had to come from the anti-aging field, because that's what we focus on: protecting all cells at once," Longo said.

"What really was missing was a perspective of someone from the aging field to give this field a boost," UCLA's Cohen said.

The idea for the study came from the Longo group's previous research on aging in cellular systems, primarily lowly baker's yeast.

About five years ago, Longo was thinking about the genetic pathways involved both in the starvation response and in mammalian tumors.

When the pathways are silenced, starved cells go into what Longo calls a maintenance mode characterized by extreme resistance to stresses. In essence the cells are waiting out the lean period, much like hibernating animals.

But tumors by definition disobey orders to stop growing because the same genetic pathways are stuck in an "on" mode.

That could mean, Longo realized, that the starvation response might differentiate normal and cancer cells by their stress resistance, and that healthy cells might withstand much more chemotherapy than cancer cells.

The shield for healthy cells does not need to be perfect, Longo said. What matters is the difference in stress resistance between healthy and cancerous cells.

During the study, conducted both at USC and in the laboratory of Lizzia Raffaghello at Gaslini Children's Hospital in Genoa, Italy, the researchers found that current chemotherapy drugs kill as many healthy mammalian cells as cancer cells.

"(But) we reached a two to five-fold difference between normal and cancer cells, including human cells in culture. More importantly, we consistently showed that mice were highly protected while cancer cells remained sensitive," Longo said.

If healthy human cells were just twice as resistant as cancer cells, oncologists could increase the dose or frequency of chemotherapy.

"We were able to reach a 1,000-fold differential resistance using a tumor model in baker's yeast. If we get to just a 10-20 fold differential toxicity with human metastatic cancers, all of a sudden it's a completely different game against cancer," Longo said.

"Now we need to spend a lot of time talking to clinical oncologists to decide how to best proceed in the human studies."

Edith Gralla, a research professor of chemistry at UCLA, said: "It is the sort of opposite of the magic bullet. It's the magic shield."

http://www.usc.edu/

Discrimination against overweight people is as prevalent as racial discrimination

Discrimination against overweight people - particularly women - is as common as racial discrimination, according to a study by the Rudd Center for Food Policy & Obesity at Yale University.

"These results show the need to treat weight discrimination as a legitimate form of prejudice, comparable to other characteristics like race or gender that already receive legal protection," said Rebecca Puhl, research scientist and lead author.

The study documented the prevalence of self-reported weight discrimination and compared it to experiences of discrimination based on race and gender among a nationally representative sample of adults aged 25- to 74-years-old. The data was obtained from the National Survey of Midlife Development in the United States.

The study also revealed that women are twice as likely as men to report weight discrimination and that weight discrimination in the workplace and interpersonal mistreatment due to obesity is common.

The researchers found that men are not at serious risk for weight bias until their body mass index (BMI) reaches 35 or higher, while women begin experiencing a notable increase in weight discrimination risk at a BMI level of 27. BMI is the measure of body fat based on height and weight.

Co-author Tatiana Andreyava of Yale said weight discrimination is more prevalent than discrimination based on sexual orientation, nationality/ethnicity, physical disability, and religious beliefs. "However, despite its high prevalence, it continues to remain socially acceptable," she said.

http://www.yale.edu/