Tuesday, May 29, 2012

Folic acid food enrichment potentially protective against childhood cancers

Researchers from the University of Minnesota and Washington University in St. Louis have found folic acid fortification of grain products in the United States may have an impact on lowering some childhood cancers. The new research, published online May 22 in the journal Pediatrics, shows fortification does not appear to be causing childhood cancer rates to increase, and also finds a notable decrease in two types of childhood cancer.
This study was led by Amy Linabery, Ph.D., postdoctoral fellow in the University of Minnesota's Division of Pediatric Epidemiology and Clinical Research, and Kimberly Johnson, Ph.D., assistant professor in the Brown School at Washington University in St. Louis, and co-authored by Julie Ross, Ph.D., professor and director of the Division of Pediatric Epidemiology and Clinical Research at the University of Minnesota. Funding was provided by the National Institutes of Health (NIH) and the Children's Cancer Research Fund, Minneapolis.
Grain product fortification began in 1996, after the FDA determined prenatal folic acid could benefit infants by reducing the occurrence of neural tube defects (such as spina bifida) and wanted to expand the benefits to all newborns. The population-level study by Linabery and colleagues compared data for incidence of childhood cancers before and after fortification began, using statistics from the National Cancer Institute (NCI) between 1986 and 2008; more than 8,000 cancer cases were evaluated.
"We were looking to see if rates for childhood cancers dropped following the fortification mandate," said Linabery. "We were also watching closely to see if any cancers appeared to increase during the same time frame."
While some cancers appeared unaffected by the fortification, others showed a notable decrease following the FDA mandate. Specifically, both Wilms tumor, the most common type of kidney cancer in children, and primitive neuroectodermal tumor (PNET), a type of brain tumor, saw a significant decrease in occurrence following the start of grain product fortification. No cancers appeared to rise in response to fortification according to the analyzed data.
The lack of rising cancer rates suggests that the folic acid fortification does not appear to cause unintended harm for children. Linabery also points out the primary benefit of folic acid in preventing neural tube defects, adding to the case for continued fortification.
There is much more research to be done. Linabery says, "These results help generate further hypotheses regarding folic acid's potential impact in cancer biology. The data we found on Wilms tumor and PNET in children warrants a closer investigation to determine the role of folic acid

cid in possibly preventing these diseases."

Genetic test identifies eye cancer tumors likely to spread

Researchers at Washington University School of Medicine in St. Louis have developed a genetic test that can accurately predict whether the most common form of eye cancer will spread to other parts of the body, particularly the liver. In 459 patients with ocular melanoma at 12 centers in the United States and Canada, the researchers found the test could successfully classify tumors more than 97 percent of the time.
The study will appear in an upcoming issue of the journal Ophthalmology, but is now online.
"When the cancer spreads beyond the eye, it's unlikely any therapy is going to be effective," says principal investigator J. William Harbour, MD. "But it's very possible that we can develop treatments to slow the growth of metastatic tumors. The real importance of this test is that by identifying the type of tumor a patient has, we can first remove the tumor from the eye with surgery or radiation and then get those individuals at high risk into clinical trials that might be able to help them live longer."
Harbour believes the test should allow ocular oncologists to quickly evaluate the risks associated with particular tumors and to begin treatment the moment they can detect any spread of the cancer.
Melanoma of the eye is relatively rare, diagnosed in about 2,000 people in the United States each year. Advances in treatment have allowed surgeons to preserve patients' vision, but when cancer spreads beyond the eye, it often is deadly.
About a decade ago, Harbour, the Paul A. Cibis Distinguished Professor of Ophthalmology and Visual Sciences, began using gene expression profiling to monitor the activity of thousands of genes in and around ocular melanoma tumors.
"At the time, we were surprised to see that based on these gene expression profiles, the tumors clustered into two groups that corresponded, almost perfectly, to patients whose cancer spread and those whose cancer was confined within the eye," says Harbour, who directs Washington University's Center for Ocular Oncology. "Tumors with a class 1 gene expression profile, or 'signature,' very rarely spread, but those with a class 2 profile frequently develop into metastatic cancer."
Initially, Harbour's group identified differences in approximately 1,000 genes between class 1 and class 2 tumors, but they whittled down that number, hoping to develop a simple test that could be used easily by ophthalmologists. Eventually, they settled on about a dozen genes that could be evaluated in tumor samples collected with a needle biopsy.
"We went through a number of sophisticated algorithms and validations, and we came up with a group of 12 genes," he says. "We also included three more genes that don't change whether they are in tumor tissue or healthy tissue. Those genes act as our 'controls' in this prognostic test."
Testing tumor tissue from his own ocular melanoma patients at the Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University in St. Louis, Harbour found that the gene expression profile test was very good at identifying the two classes of tumors. Then he started recruiting other centers to test the method, too.
"It doesn't make for a good test if it works really well for us, but it doesn't really work for anybody else," Harbour says.
Doctors at the other centers collected tumor samples and shipped them to Harbour's lab. Not knowing anything about which tumor samples came from which patients, the lab then analyzed the samples and made predictions about which tumors were likely to spread. Although it can take up to five years before there is any evidence that cancer has spread beyond the eye, this study went back less than two years later and tested predictions against what actually had happened.
Almost 62 percent of those tested (276 patients) had class 1 tumors, which were unlikely to spread. About a year and a half after the samples were tested, only three of those tumors had metastasized. Meanwhile, 38 percent of those tested (170 patients) had class 2 tumors, indicating that spread of the cancer was more likely. In that group, 44 (26 percent) developed metastatic disease during the study period. Had patients been followed longer, more likely would have experienced spread of their cancer. Statistical predictions estimate that among class 2 patients, about 60 percent would have metastatic disease within three years, and approximately 80 percent in five years.
"In this relatively short study period, the test worked as well as in the larger group of patients as it had in our patients," Harbour says. "That was important because it validated not only that our test was an accurate predictor of which patients will develop metastasis, but it also proved that the test can be performed successfully in most other clinics. At the moment, more than 70 centers around the world are using a commercially available version of the same test."
In the past, some centers relied on a chromosome test to identify eye tumors that were likely to spread. That test looked at chromosome 3 because many ocular melanoma tumors have only one copy of that chromosome.
But the 15-gene expression profile test is more accurate. It takes a more complete "snapshot" of the entire tumor. Harbour says the results of the chromosome test can change, depending on which part of a tumor gets sampled.
"I compare it to how our brains recognize faces," he says. "We don't just focus on somebody's nose. We take in all of the information from the entire face. This test takes information from the entire tumor, so if the 'nose' in the 'picture' is out of focus for some reason, it still can analyze other things."
Another strength of the test, he says, is that it can identify which patients will need the closest monitoring.
"Here at Washington University, for example, we monitor patients with class 2 tumors every three months and can begin treatment right away if we find evidence that a tumor has spread," he says.
On the other hand, the current study found that more than 60 percent of patients with ocular melanoma have class 1 tumors. Those patients don't need to be followed with the same frequency.
"We won't have to use high-intensity surveillance on everyone, only on those patients with a class 2 molecular signature, because they're the ones at risk for metastatic cancer," Harbour says.
J. William Harbour, MD, and Washington University may receive royalties based on a license of related technology by the university to Castle Biosciences Inc. This research was not funded by Castle Biosciences, Inc.
Funding for this research comes from the National Cancer Institute and the National Eye Institute of the National Institutes of Health (NIH), the Barnes-Jewish Hospital Foundation, Kling Family Foundation, Tumori Foundation, Horncreast Foundation, a Research to Prevent Blindness David F. Weeks Professorship and a Research to Prevent Blindness Inc. unrestricted grant.

New TB test promises to be cheap and fast

Biomedical engineers at UC Davis have developed a microfluidic chip to test for latent tuberculosis. They hope the test will be cheaper, faster and more reliable than current testing for the disease. "Our assay is cheaper, reusable, and gives results in real time," said Ying Liu, a research specialist working with Professor Alexander Revzin in the UC Davis Department of Biomedical Engineering.
The team has already conducted testing of blood samples from patients in China and the United States.
About one-third of the world's population is infected with the bacteria that cause tuberculosis, a disease that kills an estimated 1.5 million people worldwide every year, according to the U.S. Centers for Disease Control and Prevention.
Most infected people have latent TB, in which the bacteria are kept in check by the immune system. Patients become sick only when the immune system is compromised, enabling the bacteria to become active. People with HIV are at especially high risk.
Biomedical engineers at UC Davis have developed a microfluidic chip to test for latent tuberculosis. They hope the test will be cheaper, faster and more reliable than current testing for the disease. "Our assay is cheaper, reusable, and gives results in real time," said Ying Liu, a research specialist working with Professor Alexander Revzin in the UC Davis Department of Biomedical Engineering.
The team has already conducted testing of blood samples from patients in China and the United States.
About one-third of the world's population is infected with the bacteria that cause tuberculosis, a disease that kills an estimated 1.5 million people worldwide every year, according to the U.S. Centers for Disease Control and Prevention.
Biomedical engineers at UC Davis have developed a microfluidic chip to test for latent tuberculosis. They hope the test will be cheaper, faster and more reliable than current testing for the disease. "Our assay is cheaper, reusable, and gives results in real time," said Ying Liu, a research specialist working with Professor Alexander Revzin in the UC Davis Department of Biomedical Engineering.
The team has already conducted testing of blood samples from patients in China and the United States.
About one-third of the world's population is infected with the bacteria that cause tuberculosis, a disease that kills an estimated 1.5 million people worldwide every year, according to the U.S. Centers for Disease Control and Prevention.
Most infected people have latent TB, in which the bacteria are kept in check by the immune system. Patients become sick only when the immune system is compromised, enabling the bacteria to become active. People with HIV are at especially high risk.
Current tests for latent TB are based on detecting interferon-gamma, a disease-fighting chemical made by cells of the immune system. Commercially available tests require sending samples to a lab, and can be used just once.
Liu and Revzin used a novel approach: They coated a gold wafer with short pieces of a single-stranded DNA segment known to stick specifically to interferon-gamma. They then mounted the wafer in a chip that has tiny channels for blood samples. If interferon-gamma is present in a blood sample, it sticks to the DNA, triggering an electrical signal that can be read by a clinician.
"If you see that the interferon-gamma level is high, you can diagnose latent TB," Liu said.
The researchers plan to refine the system so that the microfluidic sensor and electronic readout are integrated on a single chip.
A patent application has been filed for the technology, and the researchers hope the test can be commercialized after FDA approval. The work was supported by the National Science Foundation.
Current tests for latent TB are based on detecting interferon-gamma, a disease-fighting chemical made by cells of the immune system. Commercially available tests require sending samples to a lab, and can be used just once.
Liu and Revzin used a novel approach: They coated a gold wafer with short pieces of a single-stranded DNA segment known to stick specifically to interferon-gamma. They then mounted the wafer in a chip that has tiny channels for blood samples. If interferon-gamma is present in a blood sample, it sticks to the DNA, triggering an electrical signal that can be read by a clinician.
"If you see that the interferon-gamma level is high, you can diagnose latent TB," Liu said.
The researchers plan to refine the system so that the microfluidic sensor and electronic readout are integrated on a single chip.
A patent application has been filed for the technology, and the researchers hope the test can be commercialized after FDA approval. The work was supported by the National Science Foundation.
Current tests for latent TB are based on detecting interferon-gamma, a disease-fighting chemical made by cells of the immune system. Commercially available tests require sending samples to a lab, and can be used just once.
Liu and Revzin used a novel approach: They coated a gold wafer with short pieces of a single-stranded DNA segment known to stick specifically to interferon-gamma. They then mounted the wafer in a chip that has tiny channels for blood samples. If interferon-gamma is present in a blood sample, it sticks to the DNA, triggering an electrical signal that can be read by a clinician.
"If you see that the interferon-gamma level is high, you can diagnose latent TB," Liu said.
The researchers plan to refine the system so that the microfluidic sensor and electronic readout are integrated on a single chip.
A patent application has been filed for the technology, and the researchers hope the test can be commercialized after FDA approval. The work was supported by the National Science Foundation.

Top 10 new species list draws attention to diverse biosphere

he International Institute for Species Exploration at Arizona State University and a committee of scientists from around the world announced their picks for the top 10 new species described in 2011. This is the fifth year for the top 10 new species list, which was released May 23 to coincide with the anniversary of the birth of Carolus Linnaeus, the Swedish botanist who was responsible for the modern system of plant and animal names and classifications. On this year's top 10 new species list are a sneezing monkey, a beautiful but venomous jellyfish, an underworld worm and a fungus named for a popular TV cartoon character. The top 10 new species also include a night-blooming orchid, an ancient walking cactus creature and a tiny wasp. Rounding out this year's list are a vibrant poppy, a giant millipede and a blue tarantula.
"The top 10 is intended to bring attention to the biodiversity crisis and the unsung species explorers and museums who continue a 250-year tradition of discovering and describing the millions of kinds of plants, animals and microbes with whom we share this planet," said Quentin Wheeler, an entomologist who directs the International Institute for Species Exploration at ASU.
Members of the international committee who made their selection from more than 200 nominations look for "species that capture our attention because they are unusual or because they have traits that are bizarre," said Mary Liz Jameson, an associate professor at Wichita State University who chaired the international selection committee. "Some of the new species have interesting names; some highlight what little we really know about our planet," she said.
Images and other information about the top 10 new species, including the explorers who made the discoveries and recorded them in calendar year 2011, are online at http://species.asu.edu. Also at the site is a Google world map that pinpoints the location for each of the top 10 new species. This year's top 10 come from Brazil, Myanmar, the Dutch Caribbean, South Africa, Papua New Guinea, Spain, Borneo, Nepal, China and Tanzania.
Describing the discoveries
Sneezing monkey: Since 2000, the number of mammals discovered each year averages about 36. So it was nothing to sneeze at when a new primate came to the attention of scientists conducting a gibbon survey in the high mountains of Myanmar (formerly Burma). Rhinopithecus strykeri, named in honor of Jon Stryker, president and founder of the Arcus Foundation, is the first snub-nosed monkey to be reported from Myanmar and is believed to be critically endangered. It is distinctive for its mostly black fur and white beard and for sneezing when it rains. A video of this species in on YouTube at http://www.youtube.com/watch?v=d1VuRvRv_UU.
Bonaire banded box jelly: This strikingly beautiful yet venomous jellyfish looks like a box kite with colorful, long tails. The species name, Tamoya ohboya, was selected by a teacher as part of a citizen science project, assuming that people who are stung exclaim "Oh boy!" A video of the species, which has been spotted near the Dutch Caribbean island of Bonaire, is on YouTube at http://www.youtube.com/watch?v=PcraphPLAxY.
Devil's worm: Measuring about 0.5 millimeters (1/50 or 0.02 inches) these tiny nematodes are the deepest-living terrestrial multicellular organisms on the planet. They were discovered at a depth of 1.3 kilometers (8/10 mile) in a South African gold mine and given the name Halicephalobus mephisto in reference to the Faust legend of the devil because the new species is found at such a depth in the Earth's crust and has survived immense underground pressure as well as high temperatures (37 degrees Celsius or 98.6 degrees Fahrenheit). According to its discoverers, carbon dating indicated that the borehole water where this species lives had not been in contact with Earth's atmosphere for the last 4,000 to 6,000 years.
Night-blooming orchid: A slender night stalker is one way to describe this rare orchid from Papua New Guinea whose flowers open around 10 at night and close early the next morning. It was described by scientists from the Royal Botanic Gardens, Kew and Leiden University, who named it Bulbophyllum nocturnum from the Latin word meaning "at night." It is believed to be the first night-blooming orchid recorded among the more than 25,000 known species of orchids.
Parasitic wasp: Ants beware! This new species of parasitic wasp cruises at just one centimeter (less than half an inch) above the ground in Madrid, Spain, in search of its target: ants. With a target in sight, the teensy wasp attacks from the air like a tiny dive bomber, depositing an egg in less than 1/20 of a second. A video of the wasp, named Kollasmosoma sentum, dropping an egg on its target is on YouTube at http://www.youtube.com/watch?v=bpMGhGMWaTA.
SpongeBob SquarePants mushroom: Named Spongiforma squarepantsii, after the cartoon character SpongeBob SquarePants, this new fungi species looks more like a sponge than a typical mushroom. One of its characteristics is that its fruiting body can be squeezed like a sponge and bounce back to its normal size and shape. This fungus, which smells fruity, was discovered in forests on the island of Borneo in Malaysia.
Nepalese autumn poppy: This vibrant, tall, yellow poppy found in Nepal may have gone undescribed because of its high mountain habitat (10,827 to 13,780 feet). Named Meconopsis autumnalis for the autumn season when the plant flowers, there is evidence that this species was collected before but not recognized as new until intrepid botanists collecting plants miles from human habitation in heavy monsoon rains made the "rediscovery."
Giant millipede: A giant millipede about the length of a sausage bears the common name "wandering leg sausage," which also is at the root of its Latin name: Crurifarcimen vagans. The species holds a new record as the largest millipede (16 centimeters or about 6.3 inches) found in one of the world's biodiversity hotspots, Tanzania's Eastern Arc Mountains. The new species is about 1.5 centimeter (0.6 inch) in diameter with 56 more or less podous rings, or body segments bearing ambulatory limbs, each with two pairs of legs.
Walking cactus (lobopod fossil): Although this new species looks more like a "walking cactus" than an animal at first glance, Diania cactiformis belongs to an extinct group called the armoured Lobopodia, which had wormlike bodies and multiple pairs of legs. The fossil was discovered in Cambrian deposits about 520 million years old from southwestern China and is remarkable in its segmented legs that may indicate a common ancestry with arthropods, including insects and spiders.
Sazima's tarantula: Breathtakingly beautiful, this iridescent hairy blue tarantula is the first new animal species from Brazil to be named on the top 10 list. Pterinopelma sazimai is not the first or only blue tarantula but truly spectacular and from "island" ecosystems on flattop mountains.
Why a top 10 new species list? "The more species we discover, the more amazing the biosphere proves to be, and the better prepared we are to face whatever environmental challenges lie ahead," said the institute's Wheeler, who also is a professor in ASU's School of Sustainability and its School of Life Sciences.
"It is impossible to do justice to the species discoveries made each year by singling out just 10. Imagine being handed 18,000 newly published books packed with fantastic information and stories and before having the opportunity to read them, being asked to pick the best 10," Wheeler said. "With the help of an international committee of experts we do the best we can by picking those with flashy jackets, surprising titles and unexpected plot lines in an effort to draw attention to the whole lot.
"There are many reasons to discover and describe species, and draw attention to this work. Perhaps most obvious is environmental: Unless we know what species exist to begin with, we are powerless to detect, track or mitigate losses of biodiversity," said Wheeler. "Another is biomimetics, turning to species for clues about new and sustainable ways to meet our needs for survival, materials and designs. There is also an intergenerational ethical imperative for species exploration. Because human population levels and activities are driving extinctions, we owe to humans who follow to explore and document our flora and fauna.
"Each species provides a unique chapter in the history of life and unless we discover them now, we stand to lose an enormous amount of irreplaceable evidence about our own origins and relatives," said Wheeler, who is one of an international group of 39 scientists, scholars and engineers who provided a detailed plan in the March 30 issue of the journal Systematics and Biodiversity to chart 10 million species in less than 50 years, and called it a necessary step to sustain the planet's biodiversity.
Marking the May 23 birth of Linnaeus
The annual top 10 new species announcement commemorates the anniversary of the birth of Carolus Linnaeus, who initiated the modern system of plant and animal names and classifications. The 300th anniversary of his birth on May 23 was celebrated worldwide in 2007.
Since Linnaeus initiated the modern systems for naming plants and animals in the 18th century, nearly 2 million species have been named, described and classified. Scientists estimate there are between 8 million and 100 million species on Earth, though most set the number between 8 million to 12 million.
The list of the top 10 new species is issued annually by ASU's International Institute for Species Exploration as part of its public awareness campaign to shine attention on biodiversity and the field of taxonomy.
Taxon experts pick top 10
"The top 10 new species is all about exploration and discovery," said committee chair Jameson, "and learning more about our planet. Lewis and Clark's discoveries included the pronghorn antelope, prairie dog and prairie rose -- 250 species altogether. But our job is far from over. We need the help of citizens and scientists alike to meet this grand challenge."
Nominations for this year's top 10 list were invited through the species.asu.edu website and also generated by institute staff and committee members.
"We had well over 200 new species nominated this year, and from those, we picked some fascinating "critters," said Jameson.
"Members on the committee come from many places around the world and from many backgrounds, so we bring our own biases to the process; some of us like photosynthesizers, some like predators, some like ocean dwelling critters," she said.
"Committee members had complete freedom in making their choices and developing their own criteria, from unique attributes or surprising facts about the species to peculiar names," Wheeler noted. "I deeply appreciate the taxon experts who gave their knowledge and time to select this year's top 10. By sharing their passion for exploring the biosphere and discovering species, they spread the recognition and appreciation of the critical roles played by taxonomy, botanical gardens and natural history museums in biodiversity exploration and conservation."
In addition to Jameson, a scarab expert, other members on this year's committee included Philippe Bouchet, a marine life expert at the French National Museum of Natural History; Meg Daly, an expert in sea anemones at the Department of Evolution, Ecology and Organismal Biology, Ohio State University; Peter Kämpfer, who expertise is bacteria, Institut für Angewandte Mikrobiologie, Justus-Liebig-Universität Giessen; Niels Peder Kristensen, an expert in Lepidoptera and basal hexapods at the Natural History Museum of Denmark, Zoologisk Museum, University of Copenhagen; James Macklin, an expert on hawthorns and blackberries at the Agriculture and Agri-food Canada; Ellinor Michel, a mollusk expert at the Department of Zoology, Natural History Museum, London; John Noyes, a chalcidoid wasp expert at the Department of Entomology, Natural History Museum, London; Alan Paton, who is an expert on mints at the International Plant Names Index and Royal Botanic Gardens, Kew, UK; Andrew Polaszek, an expert on Hymenoptera (parasitoid wasps) at the Department of Entomology, Natural History Museum, London; Gideon F. Smith, an expert on succulent plants at the Biosystematics Research and Biodiversity Collections, South African National Biodiversity Institute; Antonio Valdecasas, a water mite expert at the Museo Nacional Ciencias Naturales, Madrid, Spain; and Zhi-Qiang Zhang, a mite expert at the New Zealand Arthropod Collection, Landcare Research.

Infrared light stops eye damage

Treating eyes with gentle infrared light can help prevent the damage caused by subsequent exposure to bright light, new scientific research has found.

A breakthrough by researchers at Australia's Vision Centre offers new hope to people who suffer vision loss due to constant exposure to bright sunlight or artificial lights – such as construction workers, sportspeople, fishermen, farmers, welders, actors, entertainers and others.

Dr Krisztina Valter and PhD researcher Rizalyn Albarracin at The Vision Centre and Australian National University have shown that pre-treatment with near infrared light prevents a build-up of scar tissue in the retina causing subsequent harm to sight.

“There’s a group of cells that look after our vision and work behind the scenes called Müller cells," says Ms Albarracin. "They act to protect the retina by clearing toxins and inducing healing whenever there is injury to the vision cells.”

“However, their protection is a double-edge sword for the eyes. When the retina comes under extreme stress, as when it is exposed to intensely bright light and loses a large number of vision cells, the Müller cells can over-react by multiplying and forming scar tissue behind the retina,” she says.

“When this occurs, two things happen: first, the vision cells close to where the scar tissue forms will stop working.

“Secondly, the scar tissue blocks the blood supply to the outer retina, so that other vision cells are starved of oxygen, glucose and other nutrients vital to their survival.

“As a result more vision cells die, which in turn provokes Müller cells to work even harder, forming more scar tissues and setting up a vicious cycle,” Ms Albarracin explains.

“We found that the treatment with mild NIR successfully inhibits the Müller cells from multiplying and forming scar tissue,” says team leader Dr Krisztina Valter.

“Technically, our results showed that 670 nm light pretreatment ameliorates light-induced changes in the expression of Müller-cell specific markers for structure, stress, metabolism and inflammation.

“This suggests that 670 nm light pre-treatment may promote neuroprotective effects in the retina from light-induced damage.

“Our findings indicate that it may be possible to pre-treat someone who knows that they will be exposed to bright lights and so reduce the potential damage it can cause.

“This would be very helpful for people working in bright sunlight, under powerful artificial lamps or in occupations such as welding, as it would reduce the amount of cumulative damage they can suffer to their vision of years of exposure to bright light,” Dr Valter says.

The researchers used an array of small LEDs (light emitting diodes) that have been tuned to produce near infrared light at a specific wavelength – 670 nanometres.

These units are low-cost, making a future preventative treatment for vision loss highly affordable – especially when compared with cost of lost sight, Dr Valter says.

“Near infrared therapy is very benign, easy to use and involves no discomfort to the patient,” she adds. “It is already approved by the US Food and Drug Administration for use in sports medicine, for hair loss and so on – so developing a novel therapeutic application for the eyes is likely to be less complex and protracted than, say, developing a new drug,” she adds.

The study “670nm Red Light Preconditioning Supports Müller Cell Function: Evidence from the White Light-induced Damage Model in the Rat Retina” by Rizalyn Albarracin and Krisztina Valter is published in the journal Photochemistry and Photobiology.

The Vision Centre is funded by the Australian Research Council as the ARC Centre of Excellence in Vision Science.

Future-planning brain areas found

Our ability to imagine and plan our future depends on brain regions that store general knowledge, new research shows.

Dr Muireann Irish from Neuroscience Research Australia (NeuRA) found that dementia patients who can no longer recall general knowledge – for example, the names of famous people or popular songs – are also unable to imagine themselves in the future.

"We already know that if memory of past events is compromised, as is the case in Alzheimer's disease, then the ability to imagine future scenarios is also impaired,” says Dr Irish.

"We have now discovered that damage to parts of the brain that store knowledge of facts and meanings can also produce the same effect," she says.

Thinking about the future is an important ability because it helps us to plan and anticipate the consequences of our actions.

"For example, a person with dementia who may leave the oven on, partly because they forget the appropriate action, but also because they cannot project forward in time to anticipate the dangerous consequences this might have," says Dr Irish.

Dr Irish and colleagues used MRI to study people with Alzheimer's disease (memories of past experiences are lost) as well as patients with semantic dementia who have lost the ability to remember facts (semantic memory) but have little problem remembering past experiences.

Surprisingly, she found that the semantic dementia group was as impaired as the Alzheimer's group when imagining future events, even though their memory of past experiences was relatively intact.

"This is an important finding, as it points to multiple regions in the brain that are responsible for our ability to imagine and plan for the future," she says.

This research is published in the journal Brain.

Not all animals flee warming

A new study published on Monday 28 May 2012 in the journal Nature Climate Change provides insights into why and how species are moving around the globe in response to climate warming.

Turning up the heat is opening up areas for animals that were previously too cold, leading to the expansion of species towards the poles. However, in the hottest areas of a species range, marine and terrestrial animals seem to be responding differently.

Ocean warming is causing marine species to retreat to cooler water near the poles at both ends of their normal range spectrum. But on land so far, species are staying put at the warm end of their range even though temperatures are rising.

A research team from Simon Fraser University in Canada, Deakin University and the Institute for Marine and Antarctic Studies (IMAS) at the University of Tasmania hit the library to understand how temperature constrains the cold pole-ward and warm equator-ward range boundaries of animals and how each boundary is shifting with climate warming.

The team, led by Dr Jennifer Sunday of Simon Fraser University, first gathered published data from a century of experiments that involved heating and cooling animals to find the point at which they cease functioning. The authors found the hot and cold limits for 169 cold-blooded animals, including snails, crustaceans, dragonflies, beetles, frogs, lizards and fishes.

They then examined their maps to find the upper and lower latitudes of each species’ geographic footprint. They lined up the data for each species to compare where it lived to its temperature limits.

The team found a good match in the ocean - the footprint of marine animals closely conformed to the temperature that they could potentially occupy.

However, they were surprised to find a mismatch between where land animals are found and where they could live. Most terrestrial species can cope with more tropical temperatures but are not found there.  In other words, warm temperatures aren’t limiting terrestrial species from living closer to the equator.

Why are the warm boundaries of land species less sensitive to warming?

“We think it’s a combination of three things’’ explains Dr Amanda Bates, co-author from IMAS. “A species niche isn’t just set by temperature. On land where water is key, species may be hindered more by dryness, rather than being too hot at this range boundary.

“Second, it could be rare heat waves that are actually setting boundaries on where species can live. Finally, as Darwin pointed out more than 150 years ago, there are more species and much more ecological competition toward the tropics, which may be enough to exclude some species from living in the warmer end of their potential real estate.” 

The authors call for research to better understand how climate change will affect animals, especially those on land where predicting responses to warming may be particularly difficult.

They conclude by pointing out that while chaotic species combinations may be bad news for animals on land, entire assemblages of species are likely to shift in the ocean, meaning that we can make predictions about how marine species redistribute in the face of climate change.

Blueberries aid muscle recovery

London fruit sellers may want to stock up on New Zealand blueberries after a study found athletes who eat them recover faster from exercise.

Massey School of Sport and Exercise head Associate Professor Steve Stannard worked with University colleagues and the New Zealand Institute for Plant & Food Research on the paper, which has just been published in the Journal of the International Society of Sports Nutrition.

Dr Stannard says the findings could help Olympians and other athletes return to peak performance faster after strenuous exercise.

He and his team used a novel method that compared one leg of a participant to the other leg. “We put the study participants on a Biodex machine and had them work the thigh of one leg very hard to damage the muscle,” Dr Stannard says. “They did 300 maximal eccentric contractions, which causes micro-trauma to the muscle’s fibres.”

In the first part of the study, participants were given blueberry smoothies before, during, and for two days after the exercise strength tests, and blood samples were taken to monitor the leg’s recovery. Several weeks later, the exercise was repeated on the other leg, but a smoothie without blueberries, and therefore with a different polyphenol content, was consumed instead. Ten female participants were involved in the study.

The blood samples showed eating the blueberries, although possessing a similar total antioxidant content as the control, produced a higher level of antioxidant defence in the blood. This was associated with improved rate of recovery in the first 36 hours in one particular measure of muscle performance.

Dr Stannard says it is not yet clear exactly why the blueberries help. “But it is probably linked to the superior anthocyanin content of the New Zealand blueberry fruit interacting with and assisting the body’s natural antioxidant mechanisms,” he says.

The team used New Zealand blueberries in the study, sourced from Northland. “For me the attraction of this study is that we’re using a real food,” he says. “It’s not a pill or a supplement, it’s fruit, grown in New Zealand and available at any shop.”

Plant & Food Research scientist Dr Roger Hurst says the study has come about from a building relationship with Massey’s School of Sport and Exercise in which further research on the benefits of blueberries for exercise is being undertaken.

"There is a huge amount of research still to be done. But this work is giving a wonderful indicator and we expect these exciting findings to further boost the desirability of New Zealand blueberries."

Monday, May 28, 2012

Drug shrinks brain tumours

Australian researchers have reported promising results with a new drug that shrinks brain tumours in melanoma patients. Their findings are published in The Lancet medical journal.

Medical researchers at the University of Sydney, Melanoma Institute Australia, Sydney's Westmead Hospital and Westmead Millennium Institute, say a new drug they have been testing to treat deadly melanoma in the body also shows, for the first time, an ability to shrink secondary tumours (metastases) in the brains of patients with advanced forms of the disease.

They say the new drug may add months to the lives of patients whose melanoma has spread to the brain. Most patients with brain metastases die within four months. The trial's results, however, showed brain tumours in nine of the 10 patients shrank within the first six weeks. All 10 patients survived beyond five months, two patients survived beyond 12 months. One patient was alive at 19 months.

The drug called Dabrafenib works by targeting a gene mutation found in melanoma cancer, called the BRAF mutation, which is present in 50 percent of human melanomas. The drug works by binding to the activated mutant form of the BRAF protein in the melanoma cell, causing the cell to stop proliferating. In many cases it shrinks and disappears.

The lead author of the study, Dr Georgina Long, from the University of Sydney, Melanoma Institute Australia and Westmead Hospital said, "This is the first evidence that we have a systemic drug therapy that helps prolong survival in patients with multiple melanoma brain metastases. The findings are among the most important in the history of drug treatment for melanoma.

"Currently there is no effective systemic treatment for melanoma brain metastases, and patients whose cancer has spread to the brain are frequently excluded from promising clinical trials. Until now, there has not been a single drug that has shrunk brain metastases in more than 10 out of 100 patients with metastatic melanoma. This drug had a 90 percent success rate in reducing the size of brain metastases.

"Brain metastases in melanoma are a major unsolved problem. Up to this point, melanoma has been notoriously resistant to drug therapy in general, and responses in highly lethal brain metastases are particularly uncommon. Providing these early data are supported in larger cohorts of patients and durable responses are confirmed, this activity in the brain may assist in addressing a large unmet need in patients with metastatic melanoma worldwide," Dr Long said.

Smoke effects permanent on kids

An international study, involving researchers at the Menzies Research Institute Tasmania, has found children who are exposed to their parents’ cigarette smoke may suffer an irreversible impact to their cardiovascular health later in life.

It has been previously known that passive smoke was harmful to children, but this is the first worldwide study to examine the long-term effects on blood vessel health.

Second-hand smoke kills more than 600,000 non-smokers worldwide every year, with 379,000 of these deaths related to heart disease. According to the World Health Organization (2009) about 40 per cent of the world’s children are regularly exposed to second-hand smoke at home.

Data collected for the Young Finns Study in Finland and the Childhood Determinants of Adult Health study in Australia were analysed. These two major population-based studies collected health-related data from participants during childhood and again 20 years later when they were young adults.

Named author on the study and Menzies Research Fellow, Dr Seana Gall says that for this present study participants with data on parental smoking in childhood had their blood vessel health measured in young adulthood.

“We looked at blood vessel elasticity by measuring how the ability of an artery in the arm to expand and contract. We found that people who had been exposed to parental smoking when they were children had less elastic arteries, an early indicator of poor cardiovascular health.”

“Importantly, this was not explained by differences in classical cardiovascular risk factors, including the participants’ own smoking status, and the effect was seen up to 27 years later, suggesting a long-term and irreversible effect of passive smoking in childhood on the health of arteries.”

The results highlight the importance of policies that limit children’s exposure to cigarette smoke.

The next stage of this research aims to look further into how exposure to smoking might affect other aspects of heart health.

Dr Gall explains, “We are now looking at whether being exposed to parental smoking is associated with the thickness of the walls of people’s arteries in their necks. This is known to be a predictor of whether people go on to have strokes and heart attacks.”

Novel drug beats severe malaria


A novel anti-inflammatory drug could help to improve survival in the most severe cases of malaria by preventing the immune system from causing irrevocable brain and tissue damage.

Walter and Eliza Hall Institute researchers have shown that a new class of anti-inflammatory agents, called IDR (innate defense regulator) peptides, could help to increase survival from severe clinical malaria when used in combination with antimalarial drugs.

A research team fronted by Dr Ariel Achtman and Dr Sandra Pilat-Carotta, and led by Professor Louis Schofield from the institute’s Infection and Immunity division, published the study today in the journal Science Translational Medicine.

Dr Achtman said that many drugs that prevent malaria infections are not effective in sick patients at preventing tissue damage that arises from the inflammatory immune response. “The most severe forms of malaria, such as cerebral malaria which causes brain damage, are actually the result of the immune system trying to fight infection and causing collateral damage,” she said.

Dr Pilat-Carotta said the team used a treatment approach combining drugs that suppress potentially harmful inflammation with antimalarial agents that fight the parasite, in mouse models infected with the malaria parasite Plasmodium berghei. “In this study, we showed that a new class of drugs could prevent inflammation in the brains of mice with malaria and improve their survival. This is an example of a ‘host-directed’ therapy – a treatment intended to act on the host not the parasite,” Dr Pilat-Carotta said.

Malaria kills up to one million people worldwide every year, particularly children under five and pregnant women, who often develop severe clinical symptoms such as brain damage and multiple organ failure.

Professor Schofield said up to 25 per cent of severe clinical malaria cases are fatal even with access to the best health care. “Antimalarial drugs are very effective, but only if they are given before serious clinical symptoms develop. On their own, antimalarial drugs fail in approximately one out of every four cases of severe clinical malaria, because by the time the patient arrives at a hospital they are already very sick and inflammation caused by the immune response to the parasite is causing major organ damage,” Professor Schofield said.

IDR peptides are a new class of anti-inflammatory agent developed by Professor Robert Hancock and colleagues at the University of British Columbia, Canada, which enhance beneficial aspects of the initial immune response, while dampening harmful inflammation, Professor Schofield said. “IDR peptides are also relatively cheap to produce and easy to use, making them a good option for medical treatments in developing countries,” he said.

Dr Achtman said the development of preclinical models of severe malaria could improve pre-clinical drug screening and potentially prevent some of the drug failures that happen at the human clinical trial stage. “Professor Gordon Smyth and Ms Charity Law from the institute’s Bioinformatics division used sophisticated bioinformatics-driven analyses to identify early changes to inflammatory processes, days before the mice show visible changes in malaria disease symptoms. Host-directed therapies are a good treatment option because parasites are less likely to evolve resistance, and we believe they will eventually increase the number of successful treatment interventions in the short time window between hospitalisation with severe malaria and death,” Dr Achtman said.

The research was supported by the Grand Challenges in Global Health Research program through the Foundation for the National Institutes of Health and Canadian Institutes of Health Research, National Health and Medical Research Council of Australia, and the Victorian Government.

Drug boosts stroke recovery

Without treatment, one third of people who suffer a stroke die, with another third left permanently dependent and disabled
Patients given a clot-busting drug within six hours of a stroke are more likely to make a better recovery than those who do not receive the treatment, new research has found.

The trial was set up in 2000 by the University of Sydney's Professor Richard Lindley, while he was employed at the University of Edinburgh.

The study of more than 3000 patients is the world's largest trial of the drug rt-PA and was coordinated at the University of Edinburgh. Since coming to Sydney Medical School in 2003, Professor Lindley has continued as the co-principal investigator of the research.

The findings of the study are published today in The Lancet, alongside an analysis of all other trials of the drug carried out in the past 20 years.

The trial found that following treatment with the drug rt-PA, which is given intravenously to patients who have suffered an acute ischaemic stroke, more patients were able to look after themselves.

"The trial results, together with the updated review, mean that rt-PA can now be offered to a much wider group of patients presenting with stroke", Professor Lindley said.

A patient's chances of making a complete recovery within six months of a stroke were also increased.

An ischaemic stroke happens when the brain's blood supply is interrupted by a blood clot. The damage caused can be permanent or fatal.

Researchers now know that for every 1000 patients given rt-PA within three hours of stroke, 80 more will survive and live without help from others than if they had not been given the drug.

The benefits of using rt-PA do come at a price, say researchers. Patients are at risk of death within seven days of treatment because the drug can cause a secondary bleed in the brain. The research team concluded that the benefits were seen in a wide variety of patients, despite the risks.

Stroke experts stress that these mortality figures need to be viewed in the context of deaths from stroke. Without treatment, one third of people who suffer a stroke die, with another third left permanently dependent and disabled.

Researchers say the threat of death and disability means many stroke patients are prepared to take the early risks of being treated with rt-PA to avoid being disabled.

The authors conclude that for those who do not experience bleeding, the drug improves patients' longer term recovery.

About half of those who took part in the trial were over 80.

"The trial underlines the benefits of treating patients with the drug as soon as possible and provides the first reliable evidence that treatment is effective for those aged 80 and over," Professor Lindley said.

The study also found no reason to restrict use of rt-PA - also known as alteplase - on the basis of how severe a patient's stroke has been.

Chief investigator Professor Peter Sandercock of the University of Edinburgh's Centre for Clinical Brain Sciences said: "Our trial shows that it is crucial that treatment is given as fast as possible to all suitable patients."

Protein helps body attack cancer

Scientists at the Western Australian Institute for Medical Research (WAIMR) have made exciting progress in their quest to help patients fight cancer using the body's own immune system.The Perth-based team - led by internationally renowned cancer researcher Professor Ruth Ganss - has published a paper on their discoveries in the US scientific journal Proceedings of the National Academy of Sciences.

"Until now, immunotherapy has not been very successful in treating cancer because tumours are very resistant to immune cells," said Dr Anna Johansson, from The University of Western Australia, which is affiliated with WAIMR.

"As a cancerous tumour grows, it forms a solid ball which is difficult for immune cells to get into and even if they can penetrate the tumour, the environment inside it either kills the cells or makes it difficult for them to function.

"We engineered a protein called TNF-Alpha so that it went straight to a pancreatic tumour and stayed there without toxic side effects outside the tumour.

"TNF-Alpha affected the blood vessels in the tumour in a surprising way which opened the solid ball so that immune cells could get inside.

"We thought it might damage the blood vessels because TNF-Alpha can be very toxic, but in low doses it actually improved them and increased healthy blood flow, helping immune cells to get inside the cancer."

TNF-Alpha has been shown to enhance the tumour's response to chemotherapy but until now scientists did not understand why.  This study provides insights on how low-dose TNF-Alpha works in tumour and also shows for the first time that it can be combined with immunotherapy.cancer

MIT researchers devise new means to synchronize a group of robots (w/ Video)

For several years, roboticists have been working out ways to get a group of robots to perform synchronized activities as demonstrated most often in dance routines. It’s not just about trying to create humanoid machines that can better entertain us though, it’s about getting them to perform simple small scale synchronized activities so that a means can be found to scale up such activities so that robots of the future can work together to autonomously accomplish certain goals that have been defined by their human masters. To that end, MIT researchers Patrick Bechon and Jean-Jacques Slotine have been studying ways to mimic so called quorum sensing, which some organisms use to figure out how many of their own kind are around, and then to perform actions based on it. The two have applied this principal to small dancing robots, to stunning effect. They have written a paper describing what they have learned and posted it on the preprint server arXiv.
        Up till now, most researchers have tried getting robots to move as one by programming them to communicate with one another using various kinds of networks. The drawback is that networks tend to have latency issues, which can cause a robot to get out of synch. Other researchers have tried to preprogram the same routine into each robot and then get them to start at the same time. The problem with that of course, is if one of the robots encounters a problem, such as falling, it won’t know how to catch up to the others. To get such around such issues Bechon and Slotine looked at how nature has developed a means to handle the problem.

At the beginning all the robots are waiting for my signal to start. While dancing, they are constantly synchronizing with each other, so if a robot lags behind they will wait for him and the late robot will accelerate. When I remove a robot from the choreography, the others continue dancing. When he stands up again and resumes his dance, he asks the others for a starting position. Then he goes to this position, and starts dancing. Since he starts with a little latency, he will dances a little faster and the others a little slower to synchronize. The music is played by another robot, and is a part of the synchronization process : the robots are synchronizing with the music too.
They noted that bacteria and some insects use what is known as quorum sensing, which is where each of the organisms emit a small number of molecules into the environment which the others can sense. The more members of the group, the more molecules are present, which lets each member know how many others are there and when it’s time to do something. With the robots, the team adjusted a team of dancing robots from robot maker, Aldebaran, so that each would emit data as they danced, indicating where they are in their routine. A central computer listens for the data and computes an average for the group which it sends out into the environment; each robot then listens for that average and keeps itself as close as possible to it. If something happens, say a researcher reaches in and sets one of the robots on its fanny, the robot is able to get up, listen to where everyone else is, adjust its own routine accordingly and then join in with the group, in near perfect synchronization. Eerily similar to how a human being would do it.

Thursday, May 24, 2012

C-section 'may double risk of childhood obesity'

Babies who are delivered through Caesarean section are twice as likely to become obese than those born traditionally, US research suggests.
Researchers from Boston Children's Hospital in Massachusetts found a doubling in the odds of obesity by the time the child was three years old.
The team said birth by C-section might affect bacteria in the gut, which in turn affects the way food is digested.
The study looked at 1,255 pairs of mothers and children from 1999 to 2002.
The mothers joined the study - published in the Archives of Disease in Childhood - before 22 weeks of pregnancy.
Their babies were measured and weighed at birth and this was repeated at the age of three.
Obesity risk About one in four of the deliveries were C-section births and the remainder were vaginal deliveries.
The team found a link between body mass, skin thickness and how a child was born.
They also found that mothers who delivered by C-section tended to weigh more than those delivering traditionally - something which is known to influence obesity.
But the researchers said another possible explanation was the difference in the composition of gut bacteria acquired at birth between the two delivery methods.
They suggested expectant mothers who choose a C-section should be made aware of the obesity risk to their babies.
In the UK just over 23% of births are Caesarean.
Patrick O'Brien, a spokesman for the Royal College of Obstetricians and Gynaecologists, said: "This is an interesting study, but small. It needs to be replicated in a bigger sample."

Calcium pills pose 'heart risk'

People who take calcium supplements could be increasing their risk of having a heart attack, according to researchers in Germany.
       
Calcium is often taken by older people to strengthen bones and prevent fractures.
But the study, published in the journal Heart, said the supplements "should be taken with caution".
Experts say promoting a balanced diet including calcium would be a better strategy.
The researchers at the German Cancer Research Centre, in Heidelberg, followed 23,980 people for more than a decade.
They compared the number of heart attacks in people who were taking calcium supplements with those who did not.
  'Taken with caution'
There were 851 heart attacks among the 15,959 people who did not take any supplements at all. However, people taking calcium supplements were 86% more likely to have had a heart attack during the study.
The researchers said that heart attacks "might be substantially increased by taking calcium supplements" and that they "should be taken with caution".
Dr Carrie Ruxton, from The Health Supplements Information Service, said: "Osteoporosis is a real issue for women and it is irresponsible for scientists to advise that women cut out calcium supplements on the basis of one flawed survey, particularly when the link between calcium, vitamin D and bone health is endorsed by the European Food Safety Authority."
The British Heart Foundation (BHF) said patients prescribed the supplements should keep taking their medication, but should also speak to their doctor if they were concerned.
'Not safe' Natasha Stewart, a senior cardiac nurse with the BHF, said: "This research indicates that there may be an increased risk of having a heart attack for people who take calcium supplements.
"However, this does not mean that these supplements cause heart attacks.
"Further research is needed to shed light on the relationship between calcium supplements and heart health. We need to determine whether the potential risks of the supplements outweigh the benefits calcium can give sufferers of conditions such as osteoporosis."
Ian Reid and Mark Bolland, researchers at the University of Auckland in New Zealand, said: "The evidence is also becoming steadily stronger that it is not safe, nor is it particularly effective.
"Therefore, the administration of this micro nutrient should not be encouraged; rather people should be advised to obtain their calcium intake from an appropriately balanced diet.
"We should return to seeing calcium as an important component of a balanced diet and not as a low cost panacea to the universal problem of postmenopausal bone loss."
A spokeswoman for the UK's Department of Health said it would consider the study carefully once the complete article had been published.
"The majority of people do not need to take a calcium supplement," she said.
"A healthy balanced diet will provide all the nutrients, including calcium, that they need. Good sources of calcium include milk and dairy foods, fortified dairy food alternatives, e.g. soya drink, and green leafy vegetables."
 

WHO expected to launch 'emergency plan' to eradicate polio

The World Health Organization is expected to declare polio a global emergency after outbreaks in countries previously free of the disease.
  
The WHO wants to boost programmes in Nigeria, Pakistan and Afghanistan, the only countries where the disease is still endemic.
It says tackling polio is "at a tipping point between success and failure".
India, once regarded as one of the most challenging countries, was declared free of the disease in February.
There have been large outbreaks of the virus in Africa, Tajikistan and China has had its first cases for more than a decade.
Members of the WHO, meeting in Geneva, will vote this week on whether to declare polio eradication an "emergency for public health".
The WHO estimates that failure to act could lead to as many as 200,000 paralyzed children a year worldwide within a decade.
     
Bruce Aylward, head of the WHO's polio eradication campaign, said: "Over the last 24 months on three continents - in Europe, in Africa and in Asia - we have seen horrific explosive outbreaks of the disease that affected adults, and in some cases 50% of them died.
"What it reminded people is that, if eradication fails, we are going to see an huge and vicious upsurge of this disease with consequences that it is very difficult even to foresee right now."
The WHO originally set the year 2000 as its target for polio eradication. Dr Margaret Chan, director-general of the WHO, said the organisation was now working "in emergency mode".
The BBC's Imogen Foulkes in Geneva says the programme has claimed some remarkable successes, most notably India, which was declared polio-free in February.
She says the WHO hopes to shake donor countries out of their complacency and support one last effort at eradication. The WHO believes that with one last push, the disease could be eradicated globally, she says.
It is thought conflict and a lack of trust in vaccinations mean fewer children are being immunized.
Polio is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis in a matter of hours.
One in 200 infections leads to irreversible paralysis, usually in the legs. Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.

Hormone plays surprise role in fighting skin infections

Antimicrobial peptides (AMPs) are molecules produced in the skin to fend off infection-causing microbes. Vitamin D has been credited with a role in their production and in the body's overall immune response, but scientists at the University of California, San Diego School of Medicine say a hormone previously associated only with maintaining calcium homeostasis and bone health is also critical, boosting AMP expression when dietary vitamin D levels are inadequate.
       
The finding, published in the May 23, 2012 online issue of Science Translational Medicine, more fully explains how the in different situations and presents a new avenue for treating infections, perhaps as an alternative to current antibiotic therapies.
The immunological benefits of are controversial. In cultured cell studies, the fat-soluble vitamin provides strong immunological benefits, but in repeated studies with humans and animal models, results have been inconsistent: People with low levels of dietary vitamin D do not suffer more infections. For reasons unknown, their immune response generally remains strong, undermining the touted immunological strength of vitamin D.
Working with a mouse model and cultured human cells, Gallo and colleagues discovered why: When levels of dietary vitamin D are low (it's naturally present in very few foods), production of parathyroid hormone (PTH), which normally helps modulate calcium levels in blood, is ramped up. More PTH or a related peptide called PHTrP spurs increased expression of AMPs, such as cathelicidin, which kill a broad spectrum of harmful bacteria, fungi and viruses.
"No one suspected a role for PTH or the PTH-related peptide in immunity," said Richard L. Gallo, MD, PhD, professor of medicine and chief of UCSD's Division of Dermatology and the Dermatology section of the Veterans Affairs San Diego Healthcare System. "This may help resolve some of the controversy surrounding vitamin D. It fills in the blanks."
For example, the findings relate to the on-going debate over sun exposure. Sunlight triggers the production of vitamin D. Low levels of vitamin D have been claimed in some studies to increase the risk of cardiovascular disease and cancer, but other studies have failed to confirm this. On the other hand, high levels of solar exposure that could increase vitamin D have been shown to increase the risk of skin cancer.
"Since sunlight is a carcinogen, it's a bad idea to get too much of it," said Gallo. "PTH goes up when levels of vitamin D from diet and sun exposure are low. PTH may be what permits us to have low D in the diet and not kill ourselves with too much UV radiation."
Gallo said PTH's newly revealed immunological role provides a new connection between the body's endocrine system (a system of glands secreting different regulatory hormones into the bloodstream) and its ability to fight invasive, health-harming pathogens.
While much more work remains to be done, including human studies, it's possible that PTH or PTHrP might eventually become an effective antibiotic treatment without the risk of antibiotic resistance in targeted microbes. One challenge would be how to specifically limit treatment to the targeted infection. "Maybe that could be done by developing the therapy as a cream," Gallo said.

Aspirin may prevent recurrence of deep vein blood clots

After suffering a type of blood clot called a venous thromboembolism, patients usually take a blood-thinner such as warfarin (Coumadin). But aspirin may do just as well after a period of time, according to a new Italian study. 
       
Blood-thinning, or "anticoagulant," therapy is used to prevent another clot, which occurs in about 20 percent of patients. However, extended use of warfarin can increase the risk for bleeding, so researchers wanted to know whether aspirin would be a good alternative after two years of treatment with warfarin.
"Aspirin given after a standard course of anticoagulant treatment may reduce recurrence of venous thromboembolism without increasing complications," said lead researcher Dr. Cecilia Becattini, from the Internal and Cardiovascular Medicine and Stroke Unit at the University of Perugia.
So aspirin can be an alternative after an initial period of warfarin treatment, Becattini said, and "patients could be shifted to aspirin after talking it over with their doctor."
The study was published in the May 24 issue of the New England Journal of Medicine.
An accompanying journal editorial noted that venous thromboembolism, which includes deep vein thrombosis ( in the legs) and pulmonary embolism (a clot in the lungs), occurs in two to three people per 1,000 yearly.
The danger of a venous thromboembolism is that a clot can break loose and travel to the lungs, heart or brain, resulting in a heart attack, stroke, difficulty breathing or even death.
For the study, Becattini's team randomly assigned 402 patients to receive aspirin or an inactive placebo after receiving other anticoagulant treatment for six to 18 months.
All of the patients had had a first episode of venous thromboembolism and had not had any risk factors that might have predicted it, the researchers noted.
Over two years of follow-up, 28 (6.6 percent) of those taking aspirin had a venous thromboembolism recur, compared with 43 (11.2 percent) of those receiving a placebo, the study found.
One patient in each group had an episode of major bleeding, the authors noted.
"Aspirin reduced the risk of recurrence when given to patients with unprovoked venous thromboembolism who had discontinued anticoagulant treatment, with no apparent increase in the risk of major bleeding," the researchers concluded.
Dr. Richard Becker, author of the journal editorial and professor of medicine and director of the Duke Cardiovascular Thrombosis Center at Duke University Medical Center, said, "I consider these findings important, but preliminary."
He added, "Aspirin would not at this time be considered the standard of care to reduce the recurrence of deep vein thrombosis."
Becker also noted that this study is too small to change practice.
There are two larger trials under way and if the findings support those of this study, then aspirin may be an option for some patients, particularly those patients at high risk for bleeding with warfarin, he said.
"I do not want to give the impression that the standard of care has changed because of this study," Becker said.
Bayer HealthCare helped fund the study.

British oceanographers find new species in Indian Ocean hydrothermal vents

A research team sailing on the vessel James Cook has been studying the unique habitat surrounding deep sea vents in the Indian Ocean far off the south-east coast of Africa. The vents, created by under-the-sea-floor volcanic activity, spew black cloudy liquid and create a hot hostile environment. One of them, known as the Dragon Vent, was the main focus of cameras fixed to an aquatic robot that captured the existence of some of the exotic animals that are able to live in the distinctive environment. One of those creatures, a type of yeti crab, may even be a species unknown to science.
         
The expedition, sponsored by Britain’s Natural Environment Research Council and led by Dr. Jon Copley, a marine biologist, set sail from South Africa early in November and concluded its voyage this past week. During the middle part of that trip, the team sent down a robot called Kiel 6000 which has both cameras and a means for collecting samples of marine life, to the vents to see what sorts of animals might be living down there. Other such ventures to other vents in the Indian Ocean, as well as in other oceans have shown that truly unique types of creatures have evolved that are able to flourish in such a strange part of the planet. What’s not clear, however, is how such creatures manage to move the vast distances between such vents, as the vents, just like volcanoes on land, tend to go dormant between periods of activity.
Other types of sea life found around vents include sea cucumbers, which are long and skinny and are related to sea stars and unique types of snails, shrimp and mussels.
The vents in this latest study, are part of the South West Indian Ridge, and were first noted in 2007 by a team of Chinese researchers. Vents, or fissures in the sea floor, in general were first found to exist back in 1977 and have attracted attention since that time due to the unique life forms that call such areas home, and the fact that such vents tend to create tall mineral spires that look like chimneys which also quite often contain precious metals. It’s the existence of these metals though that could pose problems for the aquatic life as humans are apt to destroy the unique ecosystem in extracting them. The Dragon Vent, for example, is likely to be impacted soon as China has just recently been granted mineral exploration and extraction rights by the body of the United Nations responsible for doling out such permission.

Deep sea animals stowaway on submarines and reach new territory

Marine scientists studying life around deep-sea vents have discovered that some hardy species can survive the extreme change in pressure that occurs when a research submersible rises to the surface. The team's findings, published in Conservation Biology, reveal how a species can be inadvertently carried by submersibles to new areas, with potentially damaging effects on marine ecosystems.
    
After using the manned submersible Alvin to collect samples of species from the Juan de Fuca Ridge under the northeastern Pacific Ocean, the team discovered 38 deep-sea limpets ( Lepetodrilus gordensis) among their sample. Intriguingly this species is believed to occur only in the vents of the Gorda Ridge, which are 635 km south of the dive site.
"The big question was, how did they get over 600 kilometers from their habitat?" said Dr. Janet Voight, from the Field Museum of Natural History in Chicago. "We discovered that the individuals must have been transported from the Gorda Ridge by our submersible. Even though we clean the submersibles after sampling we had assumed that the extreme pressure change would kill any species which are missed."
The introduction of new species to an ecosystem by humans, often inadvertently, is a big challenge to conservation. How a new species will react to new surroundings, and the effect it can have, is unpredictable. Increases in deep-sea drilling and submersible activity can increase the probability of introductions, but until now hydrothermal vents have been considered too extreme and too isolated to be a source of introduced species.
In coastal environments one of the biggest threats posed by invasive species to native species is disease, as newly introduced pathogens and parasites can cause mass mortality. Diseases that may exist in the extreme environments created by hydrothermal vents have not been well studied.
"We've discovered that it is possible to accidently introduce a species, and any potential diseases it may carry, from a deep-sea vent to a new location," concluded Voight. "This has implications for the future exploration of hydrothermal vents as it reveals the potential risk of human driven change to the ecosystem."

Skin cells to help repair broken heart muscles

LONDON: Scientists claim to have developed a new technique to mend broken hearts by turning skin stem cells into heart muscle cells, a breakthrough they say offers new hope to thousands who struggle to live with heart failure.

The new research, which was carried out on rats, opens up the prospect of reprogramming cells taken from heart failure patients that would not be rejected by their bodies, said researchers at the Technion-Israel Institute of Technology and Rambam Medical Center in Haifa, Israel. However, it would take up to a decade before trials can be conducted on humans, the scientists cautioned.

Previously skin cells taken from young and healthy people have been transformed into heart muscle cells. But, the new study, published in the European Heart Journal , was first in which stem cells taken from the skin of elderly and diseased patients, who are most likely to need such treatment, have been transformed into heart cells.

"What is new and exciting about our research is that we have shown that it's possible to take skin cells from an elderly patient with advanced heart failure and end up with his own beating cells in a laboratory dish that are healthy and young - the equivalent to the stage of his heart cells when he was just born," Lior Gepstein, who led the study, was quoted as saying by the Daily Mail.

In their study, skin cells from two male heart failure patients were reprogrammed in two ways - by delivering three genes to the cell nucleus and using a virus that delivered reprogramming information to the cell nucleus but which was capable of being removed later.

The skin cells were transformed into heart muscle cells as effectively as those from healthy and young volunteers.

Cheating on your partner can lead to heart attack

LONDON: Cheating on your partner is not just bad for your marriage but can also give you a heart attack, researchers have claimed.

The warnings come from Italian researchers who reviewed previous studies on the causes of infidelity and its effects. These showed "sudden coital death" to be much more common when a man was meeting his mistress than when he was with his wife. The researchers could not be sure why but put forward a variety of reasons, including a guilty conscience , the Daily Mail reported. The review's authors, from the University of Florence, began by scouring medical literature for research papers including the words 'unfaithfulness' , 'extramarital affairs' , 'infidelity' and 'men' .

This provided information about the type of man who is unfaithful and the potential consequences.

The analysis showed that heart attacks, including fatal ones, were relatively rare when a man was having sex with his wife at home. But when he started to play away, the dangers grew. German studies show that most men who died during sex were having an affair and meeting away from the family home.

Furred-up arteries were blamed for more than a third of the deaths the physical demands of sex are said to cause the fatty plaque that has built up inside arteries to rupture. Liaisons away from home and with younger women are particularly dangerous. The stress of satisfying a woman who is likely to be younger than the man's wife may also be to blame, as can the strain of keeping an affair secret.

A test can tell if breast cancer will recur

LONDON: Scientists have devised a new, cheap breast cancer test that can accurately predict if a tumour is likely to return after surgery, a breakthrough they say could spare women the ordeal of chemotherapy.

The test, likely to cost about £120 and expected to be available by the year end, uses a technology already available in almost all NHS labs to estimate the risk of recurrence of the most common type of the disease, called oestrogen positive (ER+) breast cancer.

At present around half of the women diagnosed with breast cancer undergo chemotherapy following their surgery to reduce the chances of the illness returning . But, scientists behind the test, called ICH4, think many don't need to have this exhausting treatment as their tumours are 'low risk' and unlikely to recur , the Daily Mail reported.

They estimate that the ICH4 test could pick out between 4,000 and 5,000 women every year in the UK alone who would not need chemotherapy, which lasts up to six months and normally causes side effects.

'Forcing men on diet makes them fatter’

LONDON: Men forced on to healthier diets by their spouses often gain weight, as they continue to eat loads of food away from home, a new research has found.

Researchers at University of Michigan School of Public Health in the US found that wives rarely consult with husbands before "putting" them on a healthier diet.

Only couples who negotiate a new "healthy" diet make progress. Otherwise, after three or four nights of a low-fat meal, men tend to slink off to an all-you-can-eat buffet , they found.

It's just easier to "pretend" to diet to maintain a happy home, said study author Derek Griffith. "The key to married men adopting a healthier diet is for couples to discuss and negotiate the new, healthier menu changes as a team," he was quoted as saying.

Griffith said physicians can help by recognising that wives play a central role in what men eat at home.

Wednesday, May 16, 2012

Too many drugs for many older patients

Older patients are increasingly prescribed multiple drugs that, when combined, can lead to negative side effects and poor health outcomes.  A new Cochrane Library evidence review reveals that little is known about the best ways to avoid inappropriate prescribing of medications for seniors or how to maximize health benefits while minimizing prescriptions.
      
According to study author Susan M. Patterson, Ph.D., of Queen’s University in Belfast, U.K., inappropriate polypharmacy contributes to around one in 10 hospital admissions. While many patients appropriately take several drugs to treat the variety of medical problems that can arise with aging, she explains, some are inappropriately prescribed combinations of drugs intended to treat not only the original problem, but side effects from those treatments, and even side effects from side effect drugs.
“It becomes a prescribing cascade,” Patterson said. “Rather than review medications and stop the offending drug, doctors just prescribe an additional drug.”
Patterson and her colleagues gathered research on studies of interventions aiming to cut down on inappropriate drug combinations for aging patients.
One study examined the benefits of using electronic decision support, a computerized program that automatically reviews a doctor’s notes and suggests ways to avoid medical errors or improve care. Other studies researched the effectiveness of complex pharmaceutical care interventions that typically combined medication review, individual patient counseling, group patient education in the community and clinical case conferences.
Patterson and her colleagues reported that the interventions that appeared to work the best involved pharmacists as part of a multidisciplinary team working together to solve this problem.
However, she notes, it was impossible to judge from these studies whether these changes in care resulted in better patient outcomes. For example, only some of the studies reported a reduction in hospital admissions or adverse drug events. Additionally, the studies reviewed gave little insight on when to best implement interventions—for example, whether it’s more effective to counsel patients once when they’re discharged from the hospital, whenever they are prescribed new drugs, or at scheduled times of the year regardless of whether their care has changed.
“We don’t know enough about the process to say what a best scenario for reducing inappropriate polypharmacy should look like,” Patterson said. “That’s where we need further research.”
Bradley Flansbaum, D.O., director of hospitalist services at Lenox Hill Hospital in New York City, agrees. He notes that most doctors would say they’re more interested in how changes in prescribing affect patients’ quality of life, something that these studies didn’t fully examine. Rather than look at whether patients are experiencing problems such as headaches or constipation from the drugs they’re on, he says, the studies instead used a checklist to measure potentially dangerous interactions. “Not to say that a checklist isn’t important, but do you want a proxy of what you’d like to measure, or to know about the adverse event itself?” he said.

Vitamin B1 biosynthesis: Think Rubik's cube

Understanding the function of the enzyme, known as HMP-P synthase, is like solving a classic Rubik's cube, said researcher Steven Ealick, because of the number of molecular rearrangements involved. But actually solving the combination will have potential implications for antibiotic development as well as for more efficient and cost effective ways of producing thiamine for food fortification, said Ealick.
Vitamin B1, which is found most widely in cereal grains, plays an essential metabolic role in all forms of life, yet its biosynthesis has not been well understood. Senior authors Ealick and Tadhg Begley, Cornell professors of chemistry and chemical biology, and first author Abhishek Chatterjee, Ph.D. '09, and colleagues report their research findings on HMP-P synthase online and in the December issue of Nature Chemical Biology (4:12).
The researchers have characterized the enzyme's structure and are poised to work out a detailed mechanism for its activity in vitamin B1, also known as thiamine, synthesis. Their structural characterization unlocks an important door toward understanding the steps needed to produce this critical molecule.
"HMP-P synthase catalyzes the most complex unresolved chemical reaction in primary metabolism," said Ealick. This reaction involves the conversion of one molecule, abbreviated AIR, into another, abbreviated HMP-P.
"If a chemist were to write a mechanism for how you get from AIR to HMP-P, it would involve 15-20 steps, and yet one enzyme -- HMP-P synthase -- catalyzes the entire reaction," Ealick said.
Defining the enzyme's structure gave Begley and Ealick the tools they need to solve the bigger puzzle: The scientists have identified how the energy needed to power such a process is produced, and more critically, they identified the enzyme's active site, where the conversion from AIR to HMP-P takes place.
Their next steps toward understanding the complex conversion include creating various mutations at this active site to stop the conversion process at different points along the pathway. From there, they hope to be able to identify intermediate molecules and experimentally work out the multistep process.
While characterizing HMP-P synthase, the researchers were surprised to learn from the enzyme's structure that it belongs to a larger superfamily of enzymes -- the radical SAM group -- that performs "heavy-duty chemistry" like the reaction that produces HMP-P.
"We didn't know this was a radical SAM enzyme until we saw that structure," said Ealick. Like other radical SAM enzymes, HMP-P synthase contains an iron-sulfur cluster that produces an unpaired electron that can initiate highly complex reactions; the problem is, this cluster is located at the opposite end of the enzyme relative to other family members, which is why a bioinformatics screen failed to identify it.
Understanding thiamine biosynthesis has several practical applications, Ealick said. Mammals do not have the ability to make thiamine and must instead ingest it, which means that pathways unique to microbial thiamine synthesis could be targets for antibiotic drug development. Additionally, instead of chemically synthesizing thiamine to fortify foods, it may eventually be possible to employ modified microorganisms as primary vitamin factories -- an advance that would greatly increase the efficiency of thiamine production while simultaneously decreasing the cost.
"Organisms are very efficient at making the molecules that they're programmed to make," said Ealick, which seems particularly true when one considers that such incredibly complex reactions can be accomplished by single enzymes.
Provided by Cornell University

 
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