January 11, 2007, 9:04 PM CT

Prehypertension In Young Linked With Heart Enlargement

Hypertension and prehypertension in adolescents and young adults was associated with a higher risk of having an abnormally enlarged heart, researchers report in Circulation: Journal of the American Heart Association.

In a study of American Indians, average age 26.5, those with hypertension or prehypertension were more likely to have changes in the heart structure associated with increased cardiovascular risk: higher left ventricular wall thickness, higher left ventricular mass and higher prevalence of left ventricular hypertrophy. The prevalence of left ventricular hypertrophy was three times higher among those with hypertension and two times higher among those with prehypertension, compared to those with normal blood pressure.

Left ventricular hypertrophy is an abnormal thickening of the muscles of the heart's left ventricle (main pumping chamber). It is associated with heart and blood vessel complications, such as heart failure.

"The findings are a wake-up call for increased preventive measures to head off heart disease with lifestyle modifications, such as reducing caloric intake and increasing physical activity in this population," said Richard B. Devereux, M.D., senior study author and professor of medicine at Weill Medical College of Cornell University in New York City.........

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January 10, 2007, 4:25 AM CT

About Children's Packed Lunches

Packed lunches taken to school by 7-year olds are even less healthy than school meals used to be before Jamie Oliver set out to reform them.

The Children of the 90s study, based at the University of Bristol, revealed today that in the year 2000, school meals were every bit as bad a Jamie Oliver suggested - but that children given packed lunches instead were even worse off nutritionally.

Dr Pauline Emmett, Nutritionist and Dietician, who is in charge of the nutritional part of Children of the 90s said: 'We compared nutrients in foods brought by hundreds of children in their packed lunches to recommendations and found that they fell short in important nutrients like potassium and zinc and were much too high in sugar and saturated fat. The foods eaten in the rest of the day did not compensate for this.

"Children who ate school dinners had higher intakes of protein and most vitamins and minerals, and lower intakes of sugar and saturated fat.

"The Food Standards Agency recommends that packed lunches should ideally contain a starchy food, a protein food, a dairy item, a vegetable/salad and a fruit. Only 3.5% of packed lunches did contain them all and almost half (44.3%) included 2 or less. Packets of crisps and chocolate biscuits were the most commonly eaten foods after white bread with some type of fat spread.........

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December 28, 2006, 8:57 PM CT

How A Protein Stabilises Microtubules

A cell is a busy place. In a permanent rush hour, molecules are transported along a dynamic motorway system made up of filaments called microtubules. Microtubules constantly grow and shrink and are rapidly assembled wherever a cargo needs to go, but during this transportation process they need to be kept stable. Scientists from the European Molecular Biology Laboratory (EMBL) have discovered for the first time that a protein stabilises microtubules by binding to their weakest part, the so-called lattice seam. The study, which appears in this week's issue of the journal Cell, also suggests that the protein creates a special surface along the seam that offers an alternative track for transportation.

The basic building blocks of microtubules are proteins called tubulins. They assemble in a single line to form so-called protofilaments, of which several combine to build a large tubulin sheet. Investigating how this sheet folds into the tube-like structures of microtubules in yeast, scientists have now discovered that a protein called Mal3p is crucial. Combining molecular techniques with a unique Electron Microscope setup based at the ETH in Zürich, they observed that Mal3p binds to the seam of the microtubule, which forms as the two sides of the tubulin sheet fold into a tube. The protein binds in a single line along the seam, seals the tube and stabilises it at its weakest point.........

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December 20, 2006, 7:14 PM CT

Glimpses Of Light From Neutrons

Scientists from the Commerce Department's National Institute of Standards and Technology (NIST) and four universities have made the first experimental observation of rare particles of light emitted during the radioactive decay of the neutron, a key building block of matter. This work confirms theoretical predictions of this type of decay of the neutron and sets the stage for a new class of tests of basic theories in particle physics.

The experiments, published in the Dec. 21, 2006, issue of Nature, were performed at the NIST Center for Neutron Research (NCNR) in Gaithersburg, Md., because of the unique instruments and expertise at the facility. The authors include scientists from the NIST Physics Laboratory, Tulane University, the University of Michigan, the University of Maryland and the University of Sussex (Brighton, England).

The team determined that slightly more than three out of 1,000 neutron decays on average (3.13 ± 0.34 x 10-3 to be precise), produce a photon (a particle of light) above an energy level that is relatively low but still observable. The measured value has only about 10 percent uncertainty, which is considered remarkable given that this decay had never been observed before.

"This measurement is difficult because the neutron lifetime is very long, so very few neutrons decay at one time, and of those that decay, very few emit a photon," says NIST physicist Jeffrey Nico, lead author of the paper. "To make it even worse, the background radiation is very large."........

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December 20, 2006, 5:06 AM CT

Androgen Therapy To Slow Progress Of Alzheimer's Disease

Experiments on mouse models of Alzheimer's disease (AD) suggest that treatment with male sex hormones might slow its progression. The findings, published in the December 20 issue of The Journal of Neuroscience, provide new insight into the relationship between testosterone loss and AD, which affects 4.5 million Americans.

Senior author Christian Pike, PhD, of the University of Southern California (USC), with colleagues at USC and the University of California, Irvine, sought to better understand the role hormones play in aging and disease. Recent studies had already established a link between testosterone loss in men and AD due to natural aging.

The research team established a correlation between low testosterone and elevated beta-amyloid (A), a protein that accumulates abnormally in AD patients. This finding, they say, suggests that testosterone depletion in aging men may be a risk factor for AD by promoting accumulation of A in the brain. Testosterone, the primary male sex hormone, is one in a group of related steroid hormones referred to as androgens. Recent studies suggest that androgens may lower A levels.

"This study raises the possibility that androgen replacement therapy might lower the risk for Alzheimer's, but this is far from proven," says Sam Gandy, MD, PhD, chair of the Alzheimer's Association's Medical and Scientific Advisory Council and director of the Farber Institute for Neurosciences at Thomas Jefferson University. "Because testosterone is rapidly converted to estrogen after entry into neurons, the new data are logical, and they dovetail well with historical data".........

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December 17, 2006, 9:36 PM CT

Brain Can Recover From Alcoholic Damage

The findings, published recently (18 December 2006) in the online edition of the journal Brain [1], used sophisticated scanning technology and computer software to measure how brain volume, form and function changed over six to seven weeks of abstinence from alcohol in 15 alcohol dependent patients (ten men, five women).

The researchers from Germany, the UK, Switzerland and Italy measured the patients' brain volume at the beginning of the study and again after about 38 days of sobriety, and they found that it had increased by an average of nearly two per cent during this time. In addition, levels of two chemicals, which are indicators for how well the brain's nerve cells and nerve sheaths are constituted, rose significantly. The increase of the nerve cell marker correlated with the patients performing better in a test of attention and concentration. Only one patient seemed to continue to lose some brain volume, and this was also the patient who had been an alcoholic for the longest time.

The leader of the research, Dr Andreas Bartsch from the University of Wuerzburg, Germany, said: "The core message from this study is that, for alcoholics, abstinence pays off and enables the brain to regain some substance and to perform better. However, our research also provides evidence that the longer you drink excessively, the more you risk losing this capacity for regeneration. Therefore, alcoholics must not put off the time when they decide to seek help and stop drinking; the sooner they do it, the better".........

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December 15, 2006, 5:06 AM CT

Punishment May Be Reduced To The Extreme Cases

Many current problems in human societies or states, such as the overexploitation of fish stock or the abuse of social welfare systems, represent a failure of co-operation. Such conflicts between social and individual interests over the use of resources, a phenomenon known as the "tragedy of the commons", could conceivably become a threat to the actual survival of humanity. One example of such a danger in our time is the unrestricted use of fossil fuels and its effects on the global climate. Scientific research has shown, however, that there are also factors that increase our willingness to co-operate such as directly punishing those exploiting a public resource for personal gain or rewarding those with a high social status (reputation). The interesting question from a political perspective would be to what extent effective reputation mechanisms could render redundant costly sanctions of defectors.

To study such social dilemmas, experimental scientists use so-called "public goods games" as a testing ground. In a typical set up, four players are asked to contribute one Euro each to a common pool of funds. The experimenter then doubles the amount in the pool and distributes it equally among all participants - irrespective of whether they have actually made a contribution or not. If all players donated e.g. one Euro, they will end up with two Euros each. But with just one player defecting, the average dividend is reduced to 1.50 Euros each; a net profit of 1.50 Euros for the "free rider" and 0.50 Euro for the co-operator. At the end of the game, each participant will be paid his or her actual earnings in cash. While such experiments usually start out cooperatively, co-operation typically breaks down after only a few repetitions, with everyone ceasing to contribute to the public good, just as in real life. Any attempt to co-operate would entail a financial loss, since the investment of one Euro yields only a return of 50 Cents to the investor.........

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December 12, 2006, 5:07 AM CT

It Gives Much More To Quitting Than Exercise

A study of more than 36,000 women by scientists from the Universities of Minnesota and Pennsylvania observed that a high level of physical activity in women who smoked reduced their risk of developing lung cancer by nearly three quarters, compared with smokers who did no exercise.

Reported in the recent issue of Cancer Epidemiology Biomarkers & Prevention, the study also found 'moderate' activity among smokers was linked to a 65 per cent risk reduction, and lower relative risks were also seen in former smokers who had moderate or high activity levels.

However, the scientists pointed out that despite seeing benefits in exercise, the absolute risk of developing lung cancer is still very large in current and former smokers regardless of activity level.

The study's lead author, Kathryn Schmitz, an assistant professor at the University of Pennsylvania, explained: "Smokers who exercise are at a 35 per cent lower risk of developing lung cancer relative to smokers who don't exercise, but if you smoke at all, your risk of developing lung cancer is 10- to 11- fold higher than if you didn't smoke".

"The most important thing a smoker can do to reduce risk is to quit smoking. That said, exercising and being active can offer a marginal change in risk," she added.........

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December 5, 2006, 4:56 AM CT

Exposures to the insecticide chlorpyrifos in pregnancy

Children who were exposed prenatally to the insecticide chlorpyrifos had significantly poorer mental and motor development by three years of age and increased risk for behavior problems, as per a peer-evaluated study published recently by the American Academy of Pediatrics in its journal, Pediatrics. Chlorpyrifos, which was banned for residential use in 2001, is still widely applied to agricultural crops in the U.S. and abroad, including a number of fruits and vegetables.

The study assessed development of approximately 250 inner-city children from New York City who were born between 1998 and 2002. By age three, the children with the highest levels of chlorpyrifos at birth (upper 20th percentile) had significantly worse mental development and poorer motor skills than children with lower exposure levels. The more highly exposed children were also more likely by age three to exhibit early indications of behavior and attention problems. The study was co-authored by scientists from the Columbia Center for Children's Environmental Health at Columbia University's Mailman School of Public Health, and from the Centers for Disease Control and Prevention.

"These findings indicate that prenatal exposure to the insecticide chlorpyrifos not only increases the likelihood of developmental delay, but may have long-term consequences for social adjustment and academic achievement" said lead author and investigator on the study, Virginia Rauh, ScD. "Relatively speaking, the insecticide effects reported here are comparable to what has been seen with exposures to other neurotoxicants such as lead and tobacco smoke".........

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December 4, 2006, 5:12 AM CT

Molecular 'marker' On Stem Cells Aids Research

A sugar molecule present on embryonic stem cells also has been found on the surface of a type of adult stem cell, a discovery that may help scientists isolate and purify adult stem cells for use in therapies aimed at bone healing, tendon repair and cartilage regeneration, scientists at UT Southwestern Medical Center report.

The molecule, called SSEA-4, was found on the surface of certain stem cells in bone marrow that give rise to fat, cartilage and bone. These so-called mesenchymal cells are a tiny component of bone marrow; the vast majority of bone marrow is made up of hematopoietic stem cells, which give rise to blood and immune cells.

Dr. Rita Perlingeiro, assistant professor in the Center for Developmental Biology and of molecular biology, said detecting SSEA-4 will aid in singling out the mesenchymal stem cells, or MSCs, for more detailed scientific study as well as for possible medical applications. The cells have shown promise in early clinical studies elsewhere, where researchers tested their use to repair bone defects and to attenuate the effects of bone loss in diseases such as osteoporosis.

The study is available online and would be reported in the Feb. 15 issue of the journal Blood.

Eventhough mesenchymal cells were discovered in the 1970s, scientists still use decades-old methods to isolate them from bone marrow, said Dr. Perlingeiro, who led the research.........

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