Heart rhythums therapy leads for heart patients

A team of researchers have designed a device to detect and correct patterns of waves which emits from the heart of a diseased patients to live long last happily

Implantable cardioverter defibrillator or ICD.
(Credit: Image courtesy of
University of Rochester Medical Center)

 Professor Arthur J. Moss, M.D., an expert in the treatment and prevention of cardiac arrhythmias and sudden cardiac death. Moss' team found that simply raising the heart rate at which the device is set to fire -- deliver therapy -- made all the difference.

Implantable cardioverter defibrillators or ICDs constantly monitor the rate and rhythm of the heart and are supposed to deliver electrical shocks in response to very fast and potentially fatal heart rhythms. In 2002, Moss and the MADIT (Multicenter Automatic Defibrillator Implantation Trial) research group showed that ICDs are extremely effective in preventing death in patients at risk of irregular heart rhythms and sudden cardiac death, including individuals who've suffered a heart attack. The work changed medical guidelines nationwide, making thousands of heart attack survivors eligible for ICD therapy. Currently, around 200,000 ICDs are implanted in the U.S. every year.

But, according to a 2008 study in the Journal of the American College of Cardiology, approximately 20 to 25 percent of defibrillator therapy is inappropriate, meaning shocks are delivered in response to less dangerous rhythms that aren't likely to pose any immediate danger to patients. Such shocks are not only painful, but can take an emotional toll as well. Data from a 2002 trial comparing anti-arrhythmic drugs and defibrillators suggested that shocks are associated with reduced mental well-being. And a recent review of more than 45 studies found that such emotional distress is not uncommon, reporting that between 11 and 28 percent of ICD patients had some form of depression and between 11 and 26 percent had an anxiety disorder.

Moss' team conducted the MADIT-RIT (Reduce Inappropriate Therapy) trial, which was sponsored by Boston Scientific, to determine if different ways of setting the device -- a complex process performed by a heart rhythm specialist prior to device implantation in a patient's chest -- could reduce the occurrence of inappropriate therapy. Boston Scientific develops and markets medical devices, including ICDs and cardiac resynchronization therapy defibrillators or CRT-Ds.

From September 2009 through October 2011 the team enrolled 1,500 patients in 98 hospital centers in the United States, Canada, Europe, Israel, and Japan. All patients had heart disease and received a Boston Scientific ICD or CRT-D.

Currently, most defibrillators are set to initiate therapy when the heart rate exceeds around 170 beats per minute, but rates of 180 or 190 are not always dangerous, are usually short-lived, and could be related to increased activity or exercise. Unfortunately, Moss says, defibrillators aren't very good at differentiating benign from malignant rhythms in this "in-between" range.

Setting the device to fire at a higher rate of 200 beats per minute reduced the risk of experiencing a first inappropriate therapy by 79 percent compared to standard programming. Fewer shocks also corresponded with less energy delivered to the heart, which study authors believe contributed to the reduced risk of death.

"There is considerable research to suggest that there is a small amount of damage to the heart muscle with each delivered shock," added Moss. "If we can eliminate the unnecessary shocks, this is going to be associated with less heart damage and improved outcomes."

The MADIT-RIT trial is the first large-scale, randomized study designed to evaluate specific programming features to reduce inappropriate therapy in patients with ICDs. The trial's sponsor, Boston Scientific, was not involved in data collection or data analysis. Moss, who has led the MADIT trials since their inception in the 1990s, holds no stock in any device company, has never been a member of any corporate speakers bureau, and since Dec. 1, 2008, has chosen not to accept honoraria from Boston Scientific for any professional activity.

In addition to Moss, Wojciech Zareba, M.D., Ph.D., Mary Brown, David Huang, M.D., Helmut Klein, M.D., and Scott McNitt from the University of Rochester Medical Center participated in the research. Researchers and physicians from Henry Ford Hospital, Hospital of the Good Samaritan, Duke University Medical Center, Tufts-New England Medical Center, Columbia University, Institute for Clinical and Experimental Medicine, University of Iowa Health Care, Tokyo Women's Medical University, and Loyola University Medical Center also contributed to the research.

Moss, who's spent a large part of his career working to improve ICD therapy, concludes, "When the findings were first uncovered there was a sincere, general enthusiasm that we had finally come to improve the therapy we've been using for 20 years, and that we've made true progress in making ICD therapy safer, more effective, and more acceptable to patients.

Sexually abused women much less likely to be screened for cervical cancer

Women who have been sexually abused as children or young adults are much less likely to get screened for cervical cancer than other women, indicates new research.

Figures published last year by the national NHS Cervical Cancer Screening Programme indicate that around one in five eligible women had not been tested for the disease within the previous five years, as recommended.

Screening can help cut the risk of developing an invasive and potentially fatal cervical cancer. And a recent audit showed that only just over a quarter of such cases in England arose in women who had attended for regular checks as part of the national screening programme.

The research team analysed the responses of 135 women to a survey posted on the website of the British charity, the National Association for People Abused in Childhood (NAPAC). Four respondents also took part in a discussion group early in 2011.

The women were asked for their views and experiences of cervical screening, and what type of abuse they had endured. Among those aged 24 to 65 -- the current age band for cervical screening in England -- three out of four (77.5%) said they had been screened at some point, and almost half had been screened within the previous five years.

But only just over four out of 10 (42%) of those aged 25 to 49 had been screened within the previous 3 years, in line with the current UK recommendation. And one in four of this age group had not been screened for more than five years while one in 10 had not been screened at all.

Among the 124 women who responded to the open ended questions about what put them off screening, 32 said they had no intention of going or going again. Two said they would rather die than endure the procedure ever again.

Almost one in four (23%) respondents made comments reflecting low self esteem, and one in five (21%) said they found the procedure painful. And almost one in three (29%) said the procedure made them feel powerless, while 38% said it evoked similar feelings to those they experienced at the time of the abuse.

One in five highlighted issues relating to trust, safety and disclosure, while one in three made at least one comment relating to fear and anxiety.

One in eight also complained that few healthcare professionals understood the impact of sexual abuse on the ability to go through with the procedure and that the screening invitation letters contain no signposting to sources of information and support for those who might have been abused.

An accompanying editorial, written by NAPAC's training and development manager Sarah Kelly, points out that the charity receives around 350 calls/emails from adult survivors every month, two thirds of whom are women.

"Self worth, self esteem, and self concept....impact on how women access health services or care for and value themselves," writes Ms Kelly.

"Many of the female survivors we hear from, talk about their fears and anxieties when accessing services, particularly sexual health, gynaecology, and breast wellbeing," she says.

And she adds: "Many survivors are aware of the increased risk of not being screened and we repeatedly hear that some would rather deal with cervical cancer if it develops than face the experience of regular testing."

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The above abstract is republished from materials provided by EA. 
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Chemists develop reversible method of tagging proteins

Chemists have developed a method that for the first time provides scientists the ability to attach chemical probes onto proteins and subsequently remove them in a repeatable cycle.

Their achievement, detailed in a paper that appears online this week in the journal Nature Methods, will allow researchers to better understand the biochemistry of naturally formed proteins in order to create better antibiotics, anti-cancer drugs, biofuels, food crops and other natural products. It will also provide scientists with a new laboratory tool they can use to purify and track proteins in living cells.

The development was the culmination of a 10 year effort by researchers in the laboratory of Michael Burkart, a professor of chemistry and biochemistry, to establish a method to both attach a chemical probe at a specific location on a protein and selectively remove it. This flexibility allows researchers to study the protein with many different functional attachments, providing versatility akin to a biochemical Swiss Army knife. The great advantage of this technique is the broad flexibility of the attachments, which can be dyes, purification agents or mimics of natural metabolic products. Each of these attachments can be used for different purposes and biological studies.

Burkart's goal in his own laboratory is to understand more about the biochemical pathways of fatty acid metabolism and the biosynthesis of other natural products. One project focuses on engineering algae in order to produce improved biofuels. In this effort, the scientists hope to maximize the production of high quality algae oils, which could be used to supplement or supplant existing fossil fuels.

"In fatty acid metabolism, the fatty acids grow from an arm that eventually curls around and starts interacting with the metabolic protein," said Burkart, who is also associate director of the San Diego Center for Algae Biotechnology, or SD-CAB, a consortium of institutions in the San Diego region working together to make biofuels from algae commercially viable as transportation fuels. "What we wanted to know was how long does the growing fatty acid get before it starts binding with the protein?"

Burkart and chemists in his laboratory -- Nicolas Kosa, Robert Haushalter and Andrew Smith -- found a way to remove the chemical probe from this metabolic protein using an enzyme called a phosphodiesterase derived from the common bacterium Pseudomonas aeruginosa. Subsequent reattachment of a fatty acid analogue reconstituted the protein complex to its natural state. By repeating the process again and again, while examining the molecular changes in the fatty acid with nuclear magnetic spectroscopy, or NMR, during different metabolic stages, the scientists were able to detail the biochemical pathway of the fatty acid metabolism in a way they had never been able to do before.

"Without this tool, we would really have very limited ways of studying the dynamics of these fundamental metabolic processes," Burkart said. "This opened the door for us to finally examine in detail the fatty acid biosynthesis shared by algae, which you have to understand if you want to engineer ways to improve the quantity of oil that's made by algae or to make different types of oil molecules in algae that are better for biofuels."

The UC San Diego chemists also used NMR to verify that the process of chemically removing and attaching the chemical probes does not degrade or alter the protein in any way. "We've shown that we can do this iteratively, at least four or five times, without any degradation of the protein," said Burkart. "The protein remains very stable and can be studied very easily."

Because these same metabolic processes are shared by the metabolism of many natural products, including anti-cancer agents, antibiotics, and natural insecticides, Burkart said this new tool should have wide application in natural product chemistry labs.

"These are fundamental biochemical pathways that we still don't fully understand," he said. "We're now learning how these basic biosynthetic enzymes work. A large majority of drugs are derived from natural products and many future medicines can result from these pathways. There's a great interest now in synthetic biology, using these pathways to make new antibiotics or new anti-cancer drugs. They're all regulated by these same types of interactions."

The UC San Diego chemists say their method of tagging and removing chemical probes from proteins should also have wide application as a general laboratory tool to visualize and track proteins on living cells, as well as manipulate them outside of the cell.

"One could attach a tag, such as biotin, that would allow the protein to be purified. Then one can clip off the tag and attach a fluorescent molecule to monitor protein interaction with other molecular partners," said Burkart. "The method could also be used for studying living cells, such as observing protein expression levels throughout the cellular life cycle. We certainly see that as a possible application."

"Dr. Burkart's new labeling technique gives scientists an unprecedented way to probe the complex catalytic machineries involved in the biosynthesis of natural products," said Barbara Gerratana of the National Institutes of Health's National Institute of General Medical Sciences, which partially funded the work. "The technology will help scientists harness these natural biochemical pathways to synthesize novel molecules for uses in a broad array of areas, including basic biomedical research and drug discovery."

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How deadly Marburg virus silences immune system: Breakthrough findings point to targets for drugs and vaccines

The Marburg virus VP35 protein (beige)
surrounds the virus's double-stranded RNA (blue),
masking it from immune system detection.
 (Image by Christina Corbaci, The Scripps Research Institute)

Scientists at The Scripps Research Institute have determined the structure of a critical protein from the Marburg virus, a close cousin of Ebola virus. These viruses cause similar diseases and are some of the deadliest pathogens on the planet, each killing up to 90 percent of those infected.

Described in the Sept. 13, 2012 publication of the journal PLoS Pathogens, the new research reveals how a key protein component of the Marburg virus, called VP35, blocks the human immune system, allowing the virus to grow unchecked. The structure provides a major step forward in understanding how the deadly virus works, and may be useful in the development of potential treatments for those infected.

"The immune system is designed to recognize certain hallmarks of virus infection," said Erica Ollmann Saphire, the Scripps Research scientist who led the effort. "When these are sensed, an immediate antiviral defense is launched. However, the Marburg and Ebola viruses mask the evidence of their own infection. By doing so, the viruses are able to replicate rapidly and overwhelm the patient's ability to launch an effective defense."

Deadly Outbreaks

Ebola virus outbreaks have occurred in the last month in both Uganda and the Democratic Republic of the Congo, while Marburg virus broke out in Angola in 2005 to 2006 and again in Uganda in 2007. The Angolan Marburg virus outbreak began in a pediatric ward and killed 88 percent of those it infected. The virus has since been imported into the United States (Colorado) and the Netherlands by tourists who had visited Africa.

There is currently no cure for Marburg hemorrhagic fever. The virus is spread when people come into contact with the bodily fluids of a person or animal who is already infected. The best treatment consists of administering fluids and taking protective measures to ensure containment, like isolating the patient and washing sheets with bleach.

Most people, however, die within two weeks of exposure from a combination of dehydration, massive bleeding, and shock. A smaller number of people have stronger and immediate immune responses against the virus and survive.

A New Roadmap for Defense

The breakthrough described in the PLoS Pathogens article explains a key reason why the viruses are so deadly and provides the necessary templates to develop drugs to treat the infection.

The study's lead author, Research Associate Shridhar Bale, explains that a key signature of Marburg virus infection is the double-stranded RNA that results from its replication inside cells. When human immune system proteins detect this virus-specific RNA, they sound an alarm to signal the rest of the immune system to respond. The new research describes how the VP35 protein of the Marburg virus binds to the viral double-stranded RNA and hides it to prevent the alarm from being sounded.

The new research also revealed a surprise. Images from the Marburg virus reveal the VP35 protein spirals around the double-stranded RNA, enveloping it completely. This is in contrast to previous images of the similar VP35 protein from Ebola virus that showed it only capping the ends of the RNA, leaving the center of the RNA helix exposed for possible recognition.

In addition to Ollmann Saphire and Bale, the article, "Marburg virus VP35 can both fully coat the backbone and cap the ends of dsRNA for interferon antagonism," was authored by Jean-Philippe Julien, Zachary A. Bornholdt, Michelle A. Zandonatti, Gerard J.A. Kroon, Christopher R. Kimberlin, Ian J. MacRae, and Ian A. Wilson of The Scripps Research Institute, and Peter Halfmann, John Kunert, and Yoshihiro Kawaoka of the University of Wisconsin.

Support for the research was provided by grants from the Burroughs Wellcome Fund and The Skaggs Institute for Chemical Biology at Scripps Research.

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DNA wires' could help physicians diagnose disease

Credit: Comstock/Thinkstock

Scientists have found that Mother Nature uses DNA as a wire to detect the constantly occurring genetic damage and mistakes that can result in diseases like cancer. DNA wires are potentially useful in identifying people at risk for certain diseases. 

That topic ― DNA wires and their potential use in identifying people at risk for certain diseases ― is the focus of a plenary talk on August 19 during the 244th National Meeting & Exposition of the American Chemical Society in Philadelphia, Pennsylvania.

"DNA is a very fragile and special wire," said Jacqueline K. Barton, Ph.D., who delivered the talk. "You're never going to wire a house with it, and it isn't sturdy enough to use in popular electronic devices. But that fragile state is exactly what makes DNA so good as an electrical biosensor to identify DNA damage."

Barton won the U.S. National Medal of Science, the nation's highest honor for scientific achievement, for discovering that cells use the double strands of the DNA helix like a wire for signaling, which is critical to detecting and repairing genetic damage. She is a professor of chemistry and is chair of the division of chemistry and chemical engineering at the California Institute of Technology in Pasadena.

Damage is constantly occurring to DNA, Barton explained ― damage that skin cells, for instance, receive from excessive exposure to sunlight or that lung cells get hit with from carcinogens in cigarette smoke. Cells have a natural repair system in which special proteins constantly patrol the spiral-staircase architecture of DNA. They monitor the 3 billion units, or "base pairs," in DNA, looking for and mending damage from carcinogens and other sources.

Barton and other scientists noticed years ago that the DNA architecture chemically resembles the solid-state materials used in transistors and other electronic components. And DNA's bases, or units, are stacked on top of each other in an arrangement that seemed capable of conducting electricity.

"It's like a stack of copper pennies," said Barton. "And when in good condition and properly aligned, that stack of copper pennies can be conductive. But if one of the pennies is a little bit awry ― if it's not stacked so well ― then you're not going to be able to get good conductivity in it. But if those bases are mismatched or if there is any other damage to the DNA, as can happen with damage that leads to cancer, the wire is interrupted and electricity will not flow properly."

Barton's team established that the electrons that comprise a flow of electricity can move from one end of a DNA strand to the other, just as they do through an electrical wire. In one recent advance, the team was able to send electricity down a 34-nanometer-long piece of DNA. That might not sound like much -- a nanometer is one-tenth the width of a human hair. But that is just the right scale for use in medical diagnostic devices and biosensors to pick up on mutations, or changes, in DNA that could lead to cancer and other diseases.

Barton's research suggested that DNA uses its electrical properties to signal repair proteins that fix DNA damage. If the DNA is no longer conducting electricity properly, that would be a signal for repair proteins to do their thing. Barton's team is applying that knowledge in developing "DNA chips," devices that take advantage of DNA's natural electrical conductivity and its ability to bind to other strands of DNA that have a complementary sequence of base units, and thus probe that sequence for damage. Such a DNA chip would help diagnose disease risk by changes in electrical conductivity resulting from mutations or some other damage.

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The above abstract is republished from materials provided by ACS. 
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Full color images at 100,000 dots-per-inch resolution, using metal-laced nano-structures

Inspired by colorful stained-glass windows, researchers from Singapore have demonstrated an innovative method for producing sharp, full-spectrum color images at 100,000 dpi which can be applicable in reflective color displays, anti-counterfeiting, and high-density optical data recording.

This novel breakthrough allows colouring to be treated not as an inking matter but as a lithographic matter, which can potentially revolutionise the way images are printed and be further developed for use in high-resolution reflective colour displays as well as high density optical data storage.

The inspiration for the research was derived from stained glass, which is traditionally made by mixing tiny fragments of metal into the glass. It was found that nanoparticles from these metal fragments scattered light passing through the glass to give stained glass its colours. Using a similar concept with the help of modern nanotechnology tools, the researchers precisely patterned metal nanostructures, and designed the surface to reflect the light to achieve the colour images.

"The resolution of printed colour images very much depends on the size and spacing between individual 'nanodots' of colour," explained Dr Karthik Kumar, one of the key researchers involved. "The closer the dots are together and because of their small size, the higher the resolution of the image. With the ability to accurately position these extremely small colour dots, we were able to demonstrate the highest theoretical print colour resolution of 100,000 dpi."

"Instead of using different dyes for different colours, we encoded colour information into the size and position of tiny metal disks. These disks then interacted with light through the phenomenon of plasmon resonances," said Dr Joel Yang, the project leader of the research. "The team built a database of colour that corresponded to a specific nanostructure pattern, size and spacing. These nanostructures were then positioned accordingly. Similar to a child's 'colouring-by-numbers' image, the sizes and positions of these nanostructures defined the 'numbers'. But instead of sequentially colouring each area with a different ink, an ultrathin and uniform metal film was deposited across the entire image causing the 'encoded' colours to appear all at once, almost like magic!" added Dr Joel Yang.

The researchers from IMRE had also collaborated with A*STAR's Institute of High Performance Computing (IHPC) to design the pattern using computer simulation and modelling. Dr Ravi Hegde of IHPC said, "The computer simulations were vital in understanding how the structures gave rise to such rich colours. This knowledge is currently being used to predict the behaviour of more complicated nanostructure arrays."

The researchers are currently working with Exploit Technologies Pte Ltd (ETPL), A*STAR's technology transfer arm, to engage potential collaborators and to explore licensing the technology. The research was published online on August 12, 2012 in Nature Nanotechnology.

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What sets allergies in motion?

Allergies, or hypersensitivities of the immune system, are more common than ever before. According to the Asthma and Allergies Foundation of America, one in five Americans suffers from an allergy -- from milder forms like hay fever to more severe instances, like peanut allergies which can lead to anaphylactic shock.

While medications like antihistamines can treat the symptoms of an allergic reaction, the treatment is too limited, says Prof. Ronit Sagi-Eisenberg, a cell biologist at Tel Aviv University's Sackler Faculty of Medicine. Cells release dozens of molecules during an allergic reaction, and available medications address only a small subset. Now she and her fellow researchers are working to identify what triggers allergic reactions in the body, with the goal of stopping an allergic reaction before it starts.

The answer may lie within the Rab family, a group of 60 proteins that are known to regulate the distribution of proteins throughout the body. Along with her Ph.D. student Nurit Pereg-Azouz, Prof. Sagi-Eisenberg found that 30 of these proteins determined how cells react to an allergen, and two of these have been identified for further research as instruments of preventative medication. When the chain of events leading up to an allergic reaction can be understood, drugs can be developed to inhibit the initial reaction, explains Prof. Sagi-Eisenberg. This research has been published in The Journal of Immunology.

Getting to the root

Allergic reactions can appear as rashes, respiratory difficulties, or swelling, but they're all caused by the same mechanism. When exposed to an allergen, the body activates the immune system. But mast cells, located throughout the body, sense that the immune system has mistakenly been activated against something that is not bacterial or viral, and they release biologically active molecules to create an inflammatory response.

So what causes mast cells to react? Prof. Sagi-Eisenberg and her team work to identify the exact chain of events in an allergic reaction. They looked to the Rab family of proteins as a potential source for answers, screening for the proteins' involvement in initiating allergic reaction.

"We genetically manipulated mast cells so that they contained mutated versions of these proteins, which were already active without an allergen," explains Prof. Sagi-Eisenberg. If a protein was relevant, it would cause an allergic reaction. "This new methodology allowed us to screen for the functional impact of each member of this family, determining if they either inhibited or activated the allergic process."

In the end, the researchers flagged 30 proteins that were relevant to the process of creating an allergic reaction in the body, and have identified two that appear to be the most involved. Further research will use these two proteins as tools to gain more understanding of allergic reactions.

Targeted drugs could prevent allergic reaction

An allergic reaction is not only a function of two proteins interacting -- it's the result of a chain of events. By identifying crucial links in such a chain, researchers can create targeted drugs that break the chain. New medications that target tumor cells, for example, are directed at halting the tumor's ability to function and grow, starving it of crucial blood and oxygen supplies. Prof. Sagi-Eisenberg envisions similar medications for allergies, with medications that address the source of the allergic reaction instead of the symptoms.

The need for such medications is pressing. Steroids, the only available type of drug that effectively prevents mast cells from secreting biologically active agents, also cause harm to kidneys, bones, and the immune system. Patients may suffer more from the treatment than they do from the allergy itself. Alternative medications that are as effective as steroids but will be devoid of their adverse side effects are desperately needed. Prof. Sagi-Eisenberg's work will help to identify proteins that can be targeted by medications without impacting the function of other cells, she hopes.

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High dietary antioxidant intake might cut pancreatic cancer risk

Increasing dietary intake of the antioxidant vitamins C, E, and selenium could help cut the risk of developing pancreatic cancer by up to two thirds, suggests new research. 

If the association turns out to be causal, one in 12 of these cancers might be prevented, suggest the researchers, who are leading the Norfolk arm of the European Prospective Investigation of Cancer (EPIC) study. Cancer of the pancreas kills more than a quarter of a million people every year around the world. And 7500 people are diagnosed with the disease every year in the UK, where it is the six commonest cause of cancer death.

The disease has the worst prognosis of any cancer, with just 3% of people surviving beyond five years. Genes, smoking, and type 2 diabetes are all risk factors, but diet is also thought to have a role, and may explain why rates vary so much from country to country, say the authors. The researchers tracked the health of more than 23,500 40 to 74 year olds, who had entered the Norfolk arm of the EPIC study between 1993 and 1997.

Each participant filled in a comprehensive food diary, detailing the types and amount of every food they ate for 7 days, as well as the methods they used to prepare it. Each entry in the food diary was matched to one of 11,000 food items, and the nutrient values calculated using a specially designed computer program (DINER). Forty nine people (55% men) developed pancreatic cancer within 10 years of entering the study. This increased to 86 (44% men) by 2010. On average, they survived 6 months after diagnosis.

The nutrient intakes of those diagnosed with the disease within 10 years of entering EPIC were compared with those of almost 4000 healthy people to see if there were any differences. The analysis showed that a weekly intake of selenium in the top 25% of consumption roughly halved their risk of developing pancreatic cancer compared with those whose intake was in the bottom 25%. And those whose vitamins C, E, and selenium intake was in the top 25% of consumption were 67% less likely to develop pancreatic cancer than those who were in the bottom 25%. If the link turns out to be causal, that would add up to the prevention of more than one in 12 (8%) of pancreatic cancers, calculate the authors.

Antioxidants may neutralize the harmful by-products of metabolism and normal cell activity -- free radicals -- and curb genetically programmed influences, as well as stimulating the immune system response, explain the authors.

Other trials using antioxidant supplements have not produced such encouraging results, but this may be because food sources of these nutrients may behave differently from those found in supplements, they say. "If a causal association is confirmed by reporting consistent findings from other epidemiological studies, then population based dietary recommendations may help to prevent pancreatic cancer," they conclude.

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New Study Suggests Moderate Alcohol Consumption May Help Prevent Bone Loss

Drinking a moderate amount of alcohol as part of a healthy lifestyle may benefit women's bone health, lowering their risk of developing osteoporosis. A new study assessed the effects of alcohol withdrawal on bone turnover in postmenopausal women who drank one or two drinks per day several times a week. Researchers at Oregon State University measured a significant increase in blood markers of bone turnover in women after they stopped drinking for just two weeks.

Low power scanning electron microscope image,
showing osteoporotic architecture in the fourth
 lumbar vertebra of an 89 year old woman.
The bone is heavily eroded in places by
 the action of osteoclasts and
 consists mainly of thin, fragile struts

Bones are in a constant state of remodeling with old bone being removed and replaced. In people with osteoporosis, more bone is lost than reformed resulting in porous, weak bones. About 80 percent of all people with osteoporosis are women, and postmenopausal women face an even greater risk because estrogen, a hormone that helps keep bone remodeling in balance, decreases after menopause.


Past studies have shown that moderate drinkers have a higher bone density than non-drinkers or heavy drinkers, but these studies have provided no explanation for the differences in bone density. Alcohol appears to behave similarly to estrogen in that it reduces bone turnover, the researchers said.


In the current study, published online July 11 in the journalMenopause, researchers in OSU’s Skeletal Biology Laboratory studied 40 early postmenopausal women who regularly had one or two drinks a day, were not on any hormone replacement therapies, and had no history of osteoporosis-related fractures.


The researchers found evidence for increased bone turnover – a risk factor for osteoporotic fractures – during the two week period when the participants stopped drinking. Even more surprising: the researchers found that less than a day after the women resumed their normal drinking, their bone turnover rates returned to previous levels.


“Drinking moderately as part of a healthy lifestyle that includes a good diet and exercise may be beneficial for bone health, especially in postmenopausal women,” said Urszula Iwaniec, associate professor in the College of Public Health and Human Sciences at OSU and one of the study’s authors. “After less than 24 hours to see such a measurable effect was really unexpected.”


Iwaniec, OSU’s Skeletal Biology Laboratory director Russell Turner, and researcher Gianni Maddalozzo assisted OSU alumna Jill Marrone with the study, which was Marrone’s master’s thesis.


This study is important because it suggests a cellular mechanism for the increased bone density often observed in postmenopausal women who are moderate drinkers, Turner said.
The researchers said many of the medications to help prevent bone loss are not only expensive, but can have unwanted side effects. While excessive drinking has a negative impact on health, drinking a glass of wine or beer regularly as part of a healthy lifestyle may be helpful for postmenopausal women.


“Everyone loses bone as they age, but not everyone develops osteoporosis,” Turner said. “Being able to identify factors, such as moderate alcohol intake, that influence bone health will help people make informed lifestyle choices.”


The study was funded by grants from the National Institutes of Health and the John C. Erkkila, M.D. Endowment for Health and Human Performance.


Karin Hardin, Adam Branscum, Kenneth Philbrick and Lynn Cialdella-Kam of OSU co-authored the study, along with Anne Breggia and Clifford Rosen of the Maine Medical Center Research Institute.


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Naturally adhesive: New glues from renewable raw materials

Until now most adhesives have been manufactured from petroleum-based materials. However, they can also be obtained from renewable raw materials -- for example from proteins, natural rubber, starch, or cellulose. Researchers are working on new formulas for industrial applications.

Glues can be obtained from renewable raw materials –
for example from proteins, natural rubber, starch, or cellulose.
(Credit: Image courtesy of Fraunhofer-Gesellschaft)

Shoes, cars, airplanes, rotor blades for wind turbines, self-adhesive notes, plasters -- this is just a sample of the many products featuring adhesives. More than 820,000 tons of adhesive were produced in Germany in 2010, according to the German Adhesives Association -- Industrieverband Klebstoffe. To this day the majority of adhesives are manufactured from petroleum-based materials. Only gradually is the industry also offering adhesives made from renewable raw materials such as starch, cellulose, dextrins, and proteins. Pioneering products featuring these new adhesives include wallpaper pastes and glue sticks.

Adhesive based on polylactic acid

In two projects, researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT are working on further new adhesive formulas based on renewable raw materials. In cooperation with the Recklinghausen site of the Westfälische Hochschule, University of Applied Sciences, and the companies Jowat, Logo tape, and Novamelt, and with support from Germany's Federal Ministry of Food, Agriculture and Consumer Protection, researchers at UMSICHT in Oberhausen are developing a pressure-sensitive adhesive for industrial applications. Products using pressure-sensitive adhesives include adhesive bandages, self-adhesive labels, and adhesive tapes. They are subject to particularly demanding requirements: They have to remain permanently adhesive at room temperature. Gentle pressure should suffice for them to adhere to almost all substrates, and yet it must be possible to remove them without leaving behind any residue. To achieve this, the adhesive force must precisely match the respective use.

Pressure-sensitive adhesives are based on backbone polymers, which give the adhesives their inner strength (cohesion). The challenge for the UMSICHT researchers is to develop a backbone polymer from the raw material polylactic acid. What makes this biological material particularly attractive is its low production cost; since lactic acid is produced on an industrial scale, costs are in the region of prices for fossil-based backbone polymers. "However, the properties of polylactic acid are completely different from those of the polymers used to date, such as polyacrylates and styrene-based block copolymers," explains Dr. Stephan Kabasci, who heads the UMSICHT renewable resources business unit. This means that the researchers have to develop a completely new formula.

Packaging using compostable films

However, adhesives are also found in many types of packaging, for example where laminating films protect foodstuffs from dirt, moisture, and chemicals. This involves covering printed packaging and printed paper products on one or both sides with a transparent, shiny, matt, or embossed plastic film. In a collaborative project, UMSICHT scientists are working with the companies Achilles Papierveredelung Bielefeld, Jowat, and Deckert Management Consultants to develop innovative adhesive systems that meet the exacting quality requirements of laminated products as well as being compostable. In pursuit of this objective, the researchers are focusing primarily on water-based dispersion adhesives, in which the adhesive components are dispersed very finely in water. They are applied to one side of the product and joined while wet.

Nature shows us another path to developing biological adhesives. The buoy barnacle (Dosima fascicularis) produces a special adhesive which it uses to attach itself tightly to flotsam. This super-adhesive is so strong that it is almost impossible to break down into its constituent parts using ordinary solvents. Another special property it has is its ability to cure under water. Researchers at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen are now trying to find out which amino acid components make up the relevant proteins. "Once we've done that, the next step will be to recreate the adhesive proteins in the laboratory," says Dr. Ingo Grunwald, expert for biological adhesives at the IFAM. Such bioadhesives are primarily of interest for medical applications, for example to close incisions or to replace or support the pins and screws used to treat bone fractures.

Injecting life-saving oxygen into a vein

Patients unable to breathe because of acute lung failure or an obstructed airway need another way to get oxygen to their blood -- and fast -- to avoid cardiac arrest and brain injury. Medical researchers have designed tiny, gas-filled microparticles that can be injected directly into the bloodstream to quickly oxygenate the blood.

The microparticles consist of a single layer of lipids (fatty molecules) that surround a tiny pocket of oxygen gas, and are delivered in a liquid solution. In a cover article in the June 27 issue of Science Translational Medicine, John Kheir, MD, of the Department of Cardiology at Boston Children's Hospital, and colleagues report that an infusion of these microparticles into animals with low blood oxygen levels restored blood oxygen saturation to near-normal levels, within seconds.

When the trachea was completely blocked -- a more dangerous "real world" scenario -- the infusion kept the animals alive for 15 minutes without a single breath, and reduced the incidence of cardiac arrest and organ injury.

The microparticle solutions are portable and could stabilize patients in emergency situations, buying time for paramedics, emergency clinicians or intensive care clinicians to more safely place a breathing tube or perform other life-saving therapies, says Kheir.

"This is a short-term oxygen substitute -- a way to safely inject oxygen gas to support patients during a critical few minutes," he says. "Eventually, this could be stored in syringes on every code cart in a hospital, ambulance or transport helicopter to help stabilize patients who are having difficulty breathing."

The microparticles would likely only be administered for a short time, between 15 and 30 minutes, because they are carried in fluid that would overload the blood if used for longer periods, Kheir says.

Kheir also notes that the particles are different from blood substitutes, which carry oxygen but are not useful when the lungs are unable to oxygenate them. Instead, the microparticles are designed for situations in which the lungs are completely incapacitated.

Kheir began investigating the idea of injectable oxygen in 2006, after caring for a little girl who sustained a severe brain injury resulting from a severe pneumonia that caused bleeding into her lungs and severely low oxygen levels. Despite the team's best efforts, she died before they could place her on a heart-lung machine. Frustrated by this, Kheir formed a team to search for another way to deliver oxygen.

"Some of the most convincing experiments were the early ones," he says. "We drew each other's blood, mixed it in a test tube with the microparticles, and watched blue blood turn immediately red, right before our eyes."

Over the years, Kheir and his team have tested various concentrations and sizes of the microparticles to optimize their effectiveness and to make them safe for injection. "The effort was truly multidisciplinary," says Kheir. "It took chemical engineers, particle scientists and medical doctors to get the mix just right."

In the studies reported in the paper, they used a device called a sonicator, which uses high-intensity sound waves to mix the oxygen and lipids together. The process traps oxygen gas inside particles averaging 2 to 4 micrometers in size (not visible without a microscope). The resulting solution, with oxygen gas making up 70 percent of the volume, mixed efficiently with human blood.

"One of the keys to the success of the project was the ability to administer a concentrated amount of oxygen gas in a small amount of liquid," Kheir says. "The suspension carries three to four times the oxygen content of our own red blood cells." Intravenous administration of oxygen gas was tried in the early 1900s, but these attempts failed to oxygenate the blood and often caused dangerous gas embolisms.

"We have engineered around this problem by packaging the gas into small, deformable particles," Kheir explains. "They dramatically increase the surface area for gas exchange and are able to squeeze through capillaries where free gas would get stuck."

The study was funded by three awards from the Technology Development Fund at Boston Children's Hospital Boston and a U.S. Department of Defense Basic Research Award to Kheir.

Story Source:
The above abstract is republished from materials provided by Newsroom, Bosten children's Hospital.
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