Un estudio subraya que los regímenes no deben prescindir de alimentos considerados erróneamente muy calóricos

La mejor manera de adelgazar es tener una dieta sana y hacer ejercicio físico. Pero, por la generalización de dietas especiales, mucha gente cree que hay que eliminar completamente alimentos de la dieta, algunos ricos en hidratos de carbono, como el pan o las patatas. Una investigación que acaba de publicar la Universidad de California y el Instituto de Tecnología de Illinois, demuestra que la gente puede mantener la patata en su dieta y aún así perder peso. Esta investigación fue presentada en la reunión anual de la Obesity Society, celebrada esta semana en Estados Unidos. El estudio trató de obtener una mejor comprensión del papel de las patatas y el índice glucémico en la pérdida de peso, en gran parte debido a que algunos han cuestionado la inclusión de las patatas en los regímenes para pérdida de peso debido a la designación de como un alto índice glucémico (HGI) los alimentos.

"Los resultados de este estudio confirman lo que los profesionales de la salud y expertos en nutrición han dicho desde hace años, cuando se trata de la pérdida de peso, la cuestión no está en la eliminación de ciertos alimentos o grupos de alimentos, más bien, se trata de reducir las calorías que cuentan", dijo el investigador principal el doctor Britt Burton-Freeman. "No hay evidencia de que las patatas, si se preparan de una manera saludable, contribuyan al aumento de peso. De hecho, estamos viendo que puede ser parte de una dieta para pérdida de peso. "Los investigadores estudiaron a 86 hombres y mujeres con sobrepeso en el transcurso de 12 semanas para medir los efectos de una dieta baja en calorías modificado índice glucémico con el agregado de las papas. Los sujetos fueron asignados aleatoriamente a tres grupos y cada uno tenía una dieta que incluía cinco a siete porciones de papas a la semana. Los resultados indicaron que los tres grupos perdieron peso.

Scientists turn a new leaf to discover a compound in daffodils that targets brain cancer

When looking for new ways to treat aggressive brain cancers, an international team of scientists turned a new leaf and "discovered" the lowly daffodil. A new research study published in the November 2010 print issue of The FASEB Journal (http://www.fasebj.org/) offers hope that a natural compound found in daffodil bulbs, called narciclasine, may be a powerful therapeutic against biologically aggressive forms of human brain cancers.
"We are planning to move a narciclasine derivative toward clinical trials in oncology within a three to four year period in order to help patients with brain cancers, including gliomas, as well as brain metastases," said Robert Kiss, Ph.D., co-author of the study from the Laboratory of Toxicology at the Institute of Pharmacy at the Université Libre de Bruxelles in Brussels, Belgium. "We hope narciclasine could be given to brain cancer patients in addition to conventional therapies."
To make this discovery, Kiss and colleagues used computer-assisted techniques to identify targets for narciclasine in cancer cells. The strongest potential candidate to emerge was the eEF1A elongation factor. Researchers then grafted human melanoma brain metastatic cells into the brains of genetically altered mice. Results showed that the injected mice survived significantly longer when treated with narciclasine than those mice left untreated. The researchers believe that narciclasine selectively inhibits the proliferation of very aggressive cancer cells, while avoiding adverse effects on normal cells. Narciclasine could be used in the near future to combat brain cancers, including gliomas, and metastases such as melanoma brain metastases.
"Scientists have been digging in odd corners to find effective treatments for brain cancer for decades, and now they've found one in daffodils." said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, "It doesn't mean that you should eat daisies or daffodils for what ails you, but that modern medicinal chemistry can pluck new chemicals from stuff that grows in the garden. This is a good one!"

MRI contrast agents change stem cell proliferation

When researchers tested three different labeling agents on three different stem cell populations to determine what effect the labeling agents had on stem cell phenotype, biological behavior and migration abilities, they found changes in stem cell proliferation depending on the type of contrast agent used.
The team of researchers from Belgium and Spain tested USPIO (ultra small superparamagnetic iron oxide) contrast agents Resovist ®, Endorem ® and Sinerem ® on mouse embryonic stem cells (mESC), rat multipotent adult progenitor cells (rMAPC) and mouse mensenchymal stem cells (mMSC). Their study is published in the current issue of Cell Transplantation (19:8), now freely available on-line at http://www.ingentaconnect.com/content/cog/ct/.
The researchers found the labeling efficiency with each of the (U)SPIOs varied significantly when different stem cell populations were compared.
"This means that labeling methods will likely need to be optimized for every cell type," said Dr. Crabbe. "Over time we saw a dilution of (U)SPIOs and a decrease of iron in the cells."
Non-invasive imaging plays an important post-transplantation role in stem cell research, but questions regarding whether the contrast agents used to track transplanted stem cells in vivo via MRI have an impact on the cells had largely gone unanswered until this study.
On the issue of whether (U)SPIO labeling has a biological affects on cells, the researchers discovered "no significant alterations" in cell phenotypes and that the label "does not significantly alter stem cell differentiation."
"Sinerem ® decreased proliferation of mMSC while both Sinerem ® and Endorem ® affected the proliferation rate of rMAPC, although prolonged culture, until seven days, resulted in restoration of the proliferation rate," noted Dr. Crabbe. "We also found that higher concentrations of Sinerem ® and Endorem ® were needed for cell labeling to achieve similar MRI detectability."
The researchers concluded that it will be necessary to evaluate the efficiency of cell labeling for every new contrast agent combination aimed at being followed in vivo by MRI. Also, the effect on biological behavior of cells should be examined. They noted that their results were limited to examining the effects of labeling on proliferation, not differentiation.
"Although labeling of stem cells with MRI is promising, there are some limitations," concluded Dr. Crabbe. "More optimal particles are needed that can be taken up without the need of potentially toxic agents. Also, there is the problem of particle dilution over time as cells divide. When grafted cells continue to proliferate, loss of signal occurs."
According to Dr. Julio Voltarelli, professor of clinical medicine and clinical immunology at the University of Sao Pãulo, Brazil and section editor for Cell Transplantation there has been a knowledge gap regarding the survival and distribution of stem cell populations used for in vivo therapy.
"Many studies have tried to close this gap by using radioactive or nonradioactive labeling of the cells in order to follow their fate in the organism," said Dr. Voltarelli. "However, this paper demonstrates that such labeling may alter stem cell behavior, such as proliferative potential, and give biased information when compared to nonlabeled cells."

**Published in "EurekAlert"

Stress tests show where bone strength comes from

Bone is extraordinarily tough considering how lightweight and porous it is – something materials scientists have struggled to explain. Now they have discovered that bone gets its strength from a combination of tiny fibres that either get stiffer or more malleable when stretched – a finding that could lead to better treatment for osteoporosis.
Around 70 per cent of bone is made up of crystals of the chalk-like mineral hydroxyapatite. These form around tough collagen fibres known as fibrils that make up most of the rest of bone.
To better understand what makes these fibres so strong, Asa Barber and Fei Hang at Queen Mary, University of London, used a new technique to directly measure the mechanical properties of individual fibrils for the first time.
Barber and Hang used scanning electron microscopy (SEM) to image the fibrils, which measure less than 100 nanometres across – over 1000 times as thin as a human hair. They used antler bone because it is a good model of human bone but more suitable for imaging because of its low water content.
The pair combined SEM with atomic force microscopy, which stretches the fibrils with a specific force. They measured the stress-strain response of six fibrils by plotting how much they stretched when a gradually increasing force was applied. At first the fibres all stretched by the same amount under the same force. However, at a certain point their responses diverged: as more force was applied, some fibres lost their shape at a quicker rate.
Stretched stiff
Others became stiffer, withstanding a force of around 1000 nanonewtons before they broke. This is roughly equivalent to the force that would be applied by the weight of one-hundredth of a grain of rice. The more malleable fibres broke at a force around 500 nanonewtons.
"The presence of collagen fibres with different mechanical properties within bone helps to increase its ability to absorb energy, and makes it such an effective and tough material," says Barber.
The researchers next used spectroscopy to investigate the chemical make-up of the samples. Their findings suggest stronger fibres have greater mineral content.
Barber said their findings could provide a better understanding of how osteoporosis and related conditions affect the mechanical properties of bone.
Jim Gallagher at the University of Liverpool, UK, wonders whether the different types of fibres exist throughout the bone: "It's interesting data, but I would like to see it repeated with more samples from different anatomical sites," he says.

Journal reference: Journal of the Royal Society Interface, DOI: 10.1098/rsif.2010.0413

**Published in "New Scientist"

Leisure-time exercise 'reduces depression risk'

The fact that people get more enjoyment from exercising during their leisure time is key
People who take regular exercise during their free time are less likely to have symptoms of depression and anxiety, a study of 40,000 Norwegians has found.
But physical activity which is part and parcel of the working day does not have the same effect, it suggests.
Writing in the British Journal of Psychiatry, the researchers said it was probably because there was not the same level of social interaction.
The charity Mind said that exercise and interaction aids our mental health.
Higher levels of social interaction during leisure time were found to be part of the reason for the link.
Researchers from the Institute of Psychiatry at King's College London teamed up with academics from the Norwegian Institute of Public Health and the University of Bergen in Norway to conduct the study.

“Start Quote Exercise gives you a natural high and is a great way to boost your mood.”End Quote Paul Farmer chief executive, Mind
Participants were asked how often, and to what degree, they undertook physical activity in their leisure time and during the course of their work.
Researchers also measured participants' depression and anxiety using the Hospital Anxiety and Depression Scale.
People who were not active in their leisure time were almost twice as likely to have symptoms of depression compared to the most active individuals, the study found.
But the intensity of the exercise did not seem to make any difference. Social benefits
Lead researcher Dr Samuel Harvey, from the Institute of Psychiatry, said: "Our study shows that people who engage in regular leisure-time activity of any intensity are less likely to have symptoms of depression.
"We also found that the context in which activity takes place is vital and that the social benefits associated with exercise, like increased numbers of friends and social support, are more important in understanding how exercise may be linked to improved mental health than any biological markers of fitness.
"This may explain why leisure activity appears to have benefits not seen with physical activity undertaken as part of a working day."
Paul Farmer, chief executive of the mental health charity Mind, said that lifestyle factors such as diet and exercise are known to have a positive impact on mental well-being.
"Exercise gives you a natural high and is a great way to boost your mood. However, another mental health benefit of physical activity is derived from social interaction.
"So going out with a running club, taking part in a team sport or working on a communal allotment is far better for your mental well-being than a physically demanding job.
"Mind has found that after just a short country walk 90% of people had increased self-esteem," Mr Farmer said.

**Published in "BBC News"

NICE to lose powers to decide on new drugs

Changes are planned to the way drugs are funded
The medicines watchdog, NICE, is to lose its power to turn down new medicines for use on the NHS.
It will give advice on which drugs are effective, but will not decide whether patients should be given treatments their doctor recommends, the Department of Health has confirmed.
Instead, groups of GPs will decide whether a drug should be funded or not.
Ministers hope to make new drugs affordable to the NHS by negotiating with pharmaceutical companies on price.
The plans, called value-based pricing, are set to come into effect in 2014. They are subject to consultation.
A Department of Health spokesperson said: "We will introduce a new system of value-based pricing which will make effective treatments affordable to the NHS.
"Our plans will ensure licensed and effective drugs are available to NHS clinicians and patients.
"We will focus NICE's role on what matters most - advising clinicians on effective treatments and quality standards - rather than making decisions on whether patients should access drugs that their doctors want to prescribe."
The National Institute for Health and Clinical Excellence's (NICE's ) guidance on recommended drugs applies to England and Wales, and also usually Northern Ireland.
“Start Quote NICE has too often misread the public mood in rejecting clinically effective drugs for rare cancers”End Quote Mike Hobday Macmillan Cancer Support
Andrew Dillon, chief executive of NICE, said: "We support moves to extend access to new treatments at prices which reflect the additional value to patients.
"NICE is the global leader in evaluating the benefits of new drugs and we anticipate being at the heart of the new arrangements."
The cancer charity, Macmillan Cancer Support, said NICE had performed an important role for the NHS but had "misread" the public mood.
Mike Hobday, Head of Policy, said: "Having a body that can say 'no' to pharmaceutical companies has been crucial in driving the price of drugs down, so that the NHS can afford to support patients more often.
"But NICE has too often misread the public mood in rejecting clinically effective drugs for rare cancers.
"It has placed insufficient weight on the importance of allowing the NHS to give patients with rare cancers the drugs that their doctors believe will extend or improve the quality of their lives."
He said the charity was talking to the government to ensure that the NHS would be able to provide all cancer patients with clinically effective drugs recommended by their doctors.
Health think tank, The King's Fund, said NICE had made "significant progress" in providing an evidence-based approach to decisions on the cost effectiveness of drugs.
This had helped the NHS get more value from the way it spends its money, although it had not eliminated local variation, said chief economist Professor John Appleby.
He added: "With the NHS budget under huge pressure, it will be essential that the new arrangements work to generate more benefit from what already amounts to well over £10 billion spending on drugs each year."

**Published in "BBC News"

Allergan posts third-quarter loss on Botox legal charges

Allergan posted a third-quarter loss of $671 million, compared with a profit of $179 million in the year-ago period, which was in line with analysts' expectations, due to charges related to a probe into the marketing of Botox and for the impairment of its Sanctura franchise. The drugmaker also reported that sales of pharmaceuticals for the three-month period were up 5 percent to $989 million, due in part to revenue growth for Botox, which recorded sales of $342 million, up 4 percent. Total revenue was $1.2 billion, which was in line with analyst forecasts.

Reference Articles
Allergan reports third quarter 2010 operating results - (Allergan)
Allergan earnings meet expectations - (Forexpros)
Charges weigh on Allergan earnings - (MarketWatch)
Allergan swings to 3Q loss on Botox deal; year view raised - (NASDAQ)
Allergan reports inline Q3 results - (SmarTrend)

*Published in "First Word"