Friday, April 15, 2016

Tuesday, April 12, 2016

Why body weight loss in Tuberculosis Patient?

Decreased plasma leptin concentrations in tuberculosis patients are associated with wasting and inflammation.

Tuberculosis patients often suffer from severe weight loss, which is considered to be immunosuppressive and a major determinant of severity and outcome of disease. Because leptin is involved in weight regulation and cellular immunity, its possible role in tuberculosis-associated wasting was investigated. In an urban clinic in Indonesia, plasma leptin concentrations, indicators of adipocyte mass, appetite, C-reactive protein (CRP), tuberculin reactivity, and cytokine response were measured in tuberculosis patients and healthy controls. Plasma leptin concentrations were lower in patients than in controls (615 vs. 2,550 ng/liter; P < 0.001). Multivariate regression analysis showed that body fat mass and inflammation were two independent factors determining plasma leptin concentrations; there was a positive correlation between fat and leptin, whereas, unexpectedly, leptin was inversely associated with CRP and tumor necrosis factor-alpha production. Concentrations of both CRP and leptin were independently associated with loss of appetite. Our results do not support the concept that weight loss in tuberculosis is caused by enhanced production of leptin. Rather, loss of body fat leads to low plasma leptin concentrations, and prolonged inflammation may further suppress leptin production. Because leptin is important for cell-mediated immunity, low leptin production during active tuberculosis may contribute to increased disease severity, especially in cachectic patients.

Biomarker discovery offers hope for new TB vaccine

This photomicrograph reveals Mycobacterium tuberculosis bacteria using acid-fast Ziehl-Neelsen stain; Magnified 1000 X. The acid-fast stains depend on the ability of mycobacteria to retain dye when treated with mineral acid or an …more

A team of scientists led by Oxford University have made a discovery that could improve our chances of developing an effective vaccine against Tuberculosis.

The researchers have identified new biomarkers for Tuberculosis (TB) which have shown for the first time why immunity from the widely used Bacillus Calmette-Guérin (BCG) vaccine is so variable. The biomarkers will also provide valuable clues to assess whether potential new vaccines could be effective.

TB remains one of the world's major killer diseases, causing TB disease in 9.6 million people and 1.5 million deaths in 2014. The only available vaccine, Bacillus Calmette-Guérin (BCG), works well (estimated 50% effective) to prevent severe disease in children but is very variable (0% to 80% effective) in how well it protects against lung disease, particularly in countries where TB is most common.

While BCG is one of the safest and most widely used vaccines worldwide, there is one key issue: It is currently very difficult to determine whether it will work or not. This also makes it really hard to determine if any new vaccines might work.

For many vaccines, medics and scientists can use what are called immune correlates or biomarkers, typically in the blood, which can be measured to determine whether a vaccine has successfully induced immunity. Not only are these correlates useful in measuring the success of existing vaccination programmes, they are also invaluable in assessing whether potential new vaccines could be effective.

With a pressing need for a TB vaccine that is more effective than BCG, a research team drawn from a number of groups at Oxford University, working with colleagues from the South African Tuberculosis Vaccine Initiative at the University of Cape Town and the London School of Hygiene & Tropical Medicine, set out to identify immune correlates that could facilitate TB vaccine development. The team, funded by the Wellcome Trust and Aeras, and led by Professor Helen McShane and Dr Helen Fletcher, studied immune responses in infants in South Africa who were taking part in a TB vaccine trial.

Professor McShane said: 'We looked at a number of factors that could be used as immune correlates, to try and find biomarkers that will help us develop a better vaccine.'

The team carried out tests for twenty-two possible factors. One - levels of activated HLA-DR+CD4+ T-cells - was linked to higher TB disease risk. Meanwhile, BCG-specific Interferon-gamma secreting T-cells indicated lower TB risk, with higher levels of these cells directly linked to greater reduction of the risk of TB.

Antibodies to a TB protein, Ag85A, were also identified as a possible correlate. Higher levels of Ag85A antibody were associated with lower TB risk. However, the team cautions that other environmental and disease factors could also cause Ag85A antibody levels to rise and so there may not be a direct link between the antibody and TB risk.

Professor McShane said: 'These are useful results which ideally would now be confirmed in further trials. They show that antigen-specific T cells are important in protection against TB, but that activated T cells increase the risk".

Dr Helen Fletcher from the London School of Hygiene & Tropical Medicine, said: "For the first time we have some evidence of how BCG might work, and also what could block it from working. Although there is still much work to do, these findings may bring us a step closer to developing a more effective vaccine for TB."

Dr Tom Scriba from the South African Tuberculosis Vaccine Initiative said: 'TB is still a major international killer, and rates of TB disease in some areas of South Africa are among the highest in the world. These findings provide important clues about the type of immunity TB vaccines should elicit, and bring us closer to our vision, a world without TB.'

The team is continuing its work to develop a TB vaccine, aiming to protect more people from the disease.

Explore further: New tuberculosis vaccine doesn't protect infants, study finds

More information: T cell activation is an Immune Correlate of Risk in BCG vaccine infants, Nature Communications, April 12, 2016, DOI: 10.1038/NCOMMS11290

Journal reference: Nature Communications

Provided by: University of Oxford

Monday, April 11, 2016

New findings reveal social thinking in the infant brain

Credit: axelle b/public domain

An innovative collaboration between neuroscientists and developmental psychologists that investigated how infants' brains process other people's action provides the first evidence that directly links neural responses from the motor system to overt social behavior in infants.

The research will be published April 12 in Psychological Science, the peer-reviewed journal of the Association for Psychological Science.

The study involved thirty-six 7-month-old infants, who were each tested while wearing a cap that used electroencephalography (EEG) to measure brain activity. During the experiment, each infant observed an actor reach for one of two toys. Immediately after, the baby was allowed to select one of the same toys. This procedure was repeated 12 times.

Babies' brain activity predicted how they would respond to the actor's behavior. When the infants recruited their motor system while observing the actor grasp one of the toys, they subsequently imitated the actor. When they didn't imitate the actor, there was no detectable engagement of the motor system in their brain activity as they watched the actor.

"Our research provides initial evidence that motor system recruitment is contingently linked to infants' social interactive behavior," said lead author Courtney Filippi, a doctoral candidate in developmental psychology at the University of Chicago. "It provides initial evidence that recruiting the motor system during action encoding predicts infants' subsequent social interactive behavior."

Untested possibility

The researchers used EEG to measure a component of brain activity—desynchronization of activity in the mu frequency band—that has been linked to motor cortex activity in adults. Like adults, infants show this response when acting themselves and when watching others' actions, suggesting that the motor system may play a role in the perception of others' actions. Until the current study, however, this possibility had not been tested in infants.

"This research tells us that, by the middle of their first year of life, babies are beginning to be able to understand that people act intentionally—that they choose one toy over another because they want that toy," said Helen Tager-Flusberg, professor of psychological and brain sciences at Boston University, who is familiar with but was not involved in the research. "This understanding on the part of a baby involves not just seeing the other person's action, but also involves the baby's own motor system, which is recruited when he or she chooses the same toy."

Fundamentally, the researchers identified the neural processes that contribute to intelligent social behavior in infants. And it's the first evidence that motor system activation in infants predicts the imitation of others' actions, as well as an apparent understanding of others' goals.

"This is big news, that babies understand what they are observing, that there is a direct connection between observing others, understanding what others are doing, and learning how to act," said co-author Amanda Woodward, the William S. Gray Professor of Psychology at UChicago.

The researcher's methodology also broke new ground. "This is the first attempt to combine the assessment of infants' behavior—in this case, imitating the actions of another person—with measuring brain activity in infants," Tager-Flusberg said.

Proof of concept

"Probably the hardest place to study the relation between brain activity and behavior is with infants, due to limitations in the methods that can be used, and the fact that infants are infants," Woodward noted. "Our methodology represents a breakthrough and a proof of concept."

"We've worked hard over the years to develop the methods that allow us to record brain activity from infants while they are engaged in the social world," said co-author Nathan Fox, Distinguished University Professor at the University of Maryland, College Park. "The current research reflects our ability to synchronize brain and behavior in infants during the first year of life."

Although this research will not translate directly into new medical treatments or therapies, it could contribute to medical advances down the road by helping to illuminate how the human brain functions and develops, Woodward added.

"One reason to engage in basic science is to better understand the development of the brain and mind. Here we looked at the development of social cognition, social behavior, and the motor system, all of which are critical for human development and are often disrupted in developmental disabilities, including autism."

Explore further: Babies understand thought process of others at 10 months old, research finds

New study shows rich, poor have huge mortality gap in US

New study shows rich, poor have huge mortality gap in US

“As you go up in the income distribution, life expectancy continues to increase, at every point in the income distribution,” Michael Stepner says. Credit: Christine Daniloff/MIT

Poverty in the U.S. is often associated with deprivation, in areas including housing, employment, and education. Now a study co-authored by two MIT researchers has shown, in unprecedented geographic detail, another stark reality: Poor people live shorter lives, too.

More precisely, the study shows that in the U.S., the richest 1 percent of men lives 14.6 years longer on average than the poorest 1 percent of men, while among women in those wealth percentiles, the difference is 10.1 years on average.

This eye-opening gap is also growing rapidly: Over roughly the last 15 years, life expectancy increased by 2.34 years for men and 2.91 years for women who are among the top 5 percent of income earners in America, but by just 0.32 and 0.04 years for men and women in the bottom 5 percent of the income tables.

"When we think about income inequality in the United States, we think that low-income Americans can't afford to purchase the same homes, live in the same neighborhoods, and buy the same goods and services as higher-income Americans," says Michael Stepner, a PhD candidate in MIT's Department of Economics. "But the fact that they can on average expect to have 10 or 15 fewer years of life really demonstrates the level of inequality we've had in the United States."

Stepner and Sarah Abraham, another PhD candidate in MIT's Department of Economics, are among the co-authors of a newly published paper summarizing the study's findings, and have played central roles in a three-year research project establishing the results.

In addition to reporting the size and growth of the income gap, the study finds that the average lifespan varies considerably by region in the U.S. (by as much as 4.5 years), but that the sources of that regional variation are subtle, and, like the aggregate national gap, subject to further investigation.

"The patterns are not exactly what you might expect," says Abraham, noting that regional variation in longevity does not seem strongly correlated with factors such as access to health care, environmental issues, income inequality, or the job market.

"We don't find those to be as highly correlated with differences in longevity as we find measures of health behavior, such as smoking rates or obesity rates" [to be correlated with lifespan], Abraham observes.

The paper, "The Association between Income and Life Expectancy in the United States, 2001-2014," is being published today by the Journal of the American Medical Association.

The authors are Raj Chetty, a professor of economics at Stanford University; Stepner and Abraham of MIT, who are the second and third authors on the paper; Shelby Lin, an analyst with McKinsey and Company in New York; Benjamin Scuderi, a predoctorate fellow in Harvard University's Economics Department; Augustin Bergeron, a PhD candidate in Harvard University's Economics Department; Nicholas Turner of the Office of Tax Analysis in the U.S. Department of the Treasury; and David Cutler, a professor of economics at Harvard University.

The geography of mortality

The researchers looked at 1.4 billion anonymized income tax filings from the federal government, and combined that with mortality data from the years 2001 through 2014 from the Social Security Administration. This represents the most complete geographic and demographic landscape of mortality in America.

Among other things, the growth of the gap in mortality rates—by nearly three years—struck the researchers as noteworthy. To put it in perspective, they note that federal health officials estimate that curing all forms of cancer would add three years to the average lifespan.

"That change over the last 15 years is the equivalent of the richest Americans winning the war on cancer," Stepner observes.

At the same time, the researchers are quick to point out that the findings cannot immediately be reduced to simple cause-and-effect explanations. For instance, as social scientists have long observed, it is very hard to say whether having wealth leads to better health—or if health, on aggregate, is a prerequisite for accumulating wealth. Most likely, the two interact in complex ways, something the study cannot resolve.

"It's a descriptive story," Stepner says of the data.

A new puzzle emerging from the study, the authors note, is that differences in lifespan exist along the entire continuum of wealth in the U.S.; it is not as if, say, the top 10 percent of earners cluster around identical average lifespans.

"As you go up in the income distribution, life expectancy continues to increase, at every point," Stepner says.

And then there are the new geographic patterns in the findings. For instance: Eight of the 10 states with the lowest life expectancies for people in the bottom income quartile form a contiguous belt, curving around from Michigan through Ohio, Indiana, Kentucky, Tennessee, Arkansas, Oklahoma, and Kansas.

So while average lifespans for everyone are lower in some Southern states, the poor do not fare worse in those places than they do in other regions.

"The Deep South is the lowest-income area in America, but when we're looking at life expectancy conditional on having a low income, it's not worse to be poor in the Deep South than it is in other areas of America," Stepner says. "It's just that there are far more poor people living in the South."

Future research: Think local

The researchers say that more analysis on the sources of local variation in lifespans could be among the most fruitful research areas stemming from the current paper. The research team is releasing all the data from the study today as well.

Among the municipalities where low-income people have experienced the greatest increases in lifespan from 2001-2014, for example, are Toms River, New Jersey; Birmingham, Alabama; and Richmond, Virginia. Cities with the largest drops in lifespan among the poor are Tampa and Pensacola, Florida; and Knoxville, Tennessee.

"We're not making any normative statements about what policy should be, but there is a wide dispersion of [results] happening in the U.S.," Abraham says. "That might need to be addressed at a more granular level."

Places with the overall longest lifespans for the poor include New York City, with a chart-topping 81.8 years on average, as well as a passel of cities in California. The bottom of that list includes Gary, Indiana (77.4 years on average); Las Vegas; and Oklahoma City.

Among the top income earners, people live longest in Salt Lake City (87.8 years on average); Portland, Maine; and Spokane, Washington. The rich have the shortest lives in Las Vegas (84.1 years on average); Gary, Indiana; and Honolulu.

Abraham also observes that the findings could have implications for national policy programs, as well.

"Things like Social Security aren't going to be as redistributive if the richer people are getting paid for 10 more years than the poorer people," she says.

Overall, the researchers say they hope to spark a larger discussion among the research and policy communities.

"We don't have all the answers," Abraham says. "But it's really important to make these statistics widely used so people have an idea of what the magnitude of these problems is, where they might focus their attention, and why this matters."

Explore further: New report examines implications of growing gap in life span by income for entitlement programs

More information: Raj Chetty et al. The Association Between Income and Life Expectancy in the United States, 2001-2014, JAMA (). DOI: 10.1001/jama.2016.4226

Read more at: http://phys.org/news/2016-04-rich-poor-huge-mortality-gap.html#jCp

Employment status affects our morals around money

In the study 'Moral consequences of becoming unemployed', endorsed by the prestigious scientific journal PNAS, researchers at the UPV/EHU's Faculty of Economics and Business and at the University of Nottingham (UK) have analysed a moral consequence of unemployment that together with the effects it has on people's mental health, could explain why these people become disengaged from the labor market. 151 young adults in Córdoba and Bilbao were involved in the study.

As Luis Miller asserts, "in general, both people in employment and those in full-time education believe that people should be allowed to keep most of what they earn and that it is OK for those who work harder or who are more productive to earn more". He went on to say, "When people become unemployed, our study indicates that they let go of this belief. They put a higher value on the redistribution of money, which, in social terms, would mean higher taxes on those earning more in order to fund increased public spending."The authors of the study Luis Miller, lecturer at the UPV/EHU's Faculty of Economics and Business, and Paloma Ubeda, a UPV/EHU researcher, highlight the importance of understanding how becoming unemployed affects people's behaviour. Many studies link unemployment and poverty with depression, anxiety, stress, low levels of well-being and self-esteem, high suicide rates, murder, alcohol-related deaths, etc. In this study, however, the researchers have looked at a different kind of effect and have concluded that unemployment changes people's morals around the distribution of money. It should be pointed out that the study has been published in the latest edition of the PNAS, a prestigious scientific journal which publishes relatively few papers from the social sciences but which has given particular importance to this one.

"In our study," explained Paloma Úbeda, "we didn't ask the participants about re-distribution, taxes or public spending, as the responses to questions of this type could be biased by the self-interest of the interviewees. So high earners who look after their own interests would prefer lower taxes, while low earners who also have their own interests in mind would want higher taxes. What we were really interested in was understanding how, when becoming unemployed, people change the way they see what is fair in terms of re-distribution, in other words, whether they change their moral values. We found that they do; when becoming unemployed people change the way they think about fairness and re-distribution".

Unemployment leads to changes in opinions

To research people's ideals about justice, the researchers involved 151 young adults aged between 18 and 35 in the so-called "Distributive Justice Game", an experiment designed to reveal the values and preferences of the participants about fairness and re-distribution. The experiment was conducted in Bilbao and Córdoba. The game consisted of two parts.

In the first part the participants "worked" for the researchers for seven minutes. In the second part of the game each participant was given a tray divided into four sections. Each section contained a different amount of money. One of the sections belonged to the participant who had been given the tray. The other three sections belonged to the other three participants who were in their playing group. For some groups the amount of money each one received depended on how much work the people had done during the first part of the game. In others, the amount of money on the trays depended totally on luck and were not related in any way to the work each person had done. The participants could re-distribute the money among the four sections in whatever way they wanted. Each one could keep all the money, leave the tray as they had received it or re-distribute the money so that the four participants would all receive the same amount at the end of the experiment.

"We found that the employed people tended to re-distribute the money less when they knew people had earned their money in the first part," asserted Luis Miller. "By contrast, they tended to re-distribute it almost equally when they knew that the initial distributions were just due to luck".

The 151 young adults participated twice in the experiment, the first time in the spring of 2013 and the second exactly one year later. Repeating the experiment allowed the researchers to see whether the people who were employed or in full-time education during the first year of the study but ended up unemployed in the second year changed their opinions about fairness and re-distribution.

Most of those who had become unemployed re-distributed the money in such a way that the other three members of their group ended up with approximately the same amount of money irrespective of whether the money had been earned or received as a result of luck.

Paloma Úbeda added that "the extent to which people recognise the individual right to keep what they have earned has significant implications on the way people vote, on how they pay their taxes or on how they act in the labour market. However, all these implications would need to be studied in greater detail in future pieces of research".

Luis Miller concluded that "the significance of the main result of this study to understand the labour dynamics as well as the most appropriate public intervention depends to what extent the negative effect we find can be reversed. Right now, we are already working on new projects that seek to establish whether the unemployed need to re-acquire part of the values relating to effort and productivity abandoned along the way before effectively reengaging with the labour market. Then assuming they do, we would need to investigate how this new change of values takes place and also how public interventions can contribute towards enabling this process".

Explore further: Study results suggest people are less cooperative in unequal societies when wealth inequality is evident

More information: Moral consequences of becoming unemployed , PNAS,www.pnas.org/cgi/doi/10.1073/pnas.1521250113

Conscious Health

Friday, April 15, 2016

More exposure to vegetation linked with lower mortality rates in women

Tuesday, April 12, 2016

Why body weight loss in Tuberculosis Patient?

Decreased plasma leptin concentrations in tuberculosis patients are associated with wasting and inflammation.

Biomarker discovery offers hope for new TB vaccine

Monday, April 11, 2016

New findings reveal social thinking in the infant brain

New study shows rich, poor have huge mortality gap in US

Employment status affects our morals around money