Self-assembling material could lead to artificial arteries

September 30, 2015
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Illustration showing creation of synthetic capillaries from peptides and proteins (credit: QMUL)

Researchers at Queen Mary University of London (QMUL) have developed a new bioinspired process using self-assembling organic molecules that can develop into complex tubular tissue-like structures. The process could lead to creating synthetic tissues that emulate veins, arteries, or even the blood-brain barrier, and that exhibit dynamic behaviors found in biological tissues like growth, morphogenesis, and healing.

The process uses solutions of peptide and protein molecules that self-assemble to form a dynamic tissue that can be guided to grow into complex shapes without the use of molds or techniques like 3-D printing.

Adipose-derived stem cells (mADSCs) seeded onto the protein/peptide membrane (credit: QMUL)

According to the researchers, the finding could allow scientists to study diseases such as Alzheimer’s with a high level of similarity to the real tissue and create better implants, complex tissues, and more effective drug-screening methods.

The study appeared September 28 in the journal Nature Chemistry. It has been partly funded by the European Research Council.

QMUL | Demonstrating a dynamic self-assembling protein-peptide membrane

Abstract of Co-assembly, spatiotemporal control and morphogenesis of a hybrid protein–peptide system

Controlling molecular interactions between bioinspired molecules can enable the development of new materials with higher complexity and innovative properties. Here we report on a dynamic system that emerges from the conformational modification of an elastin-like protein by peptide amphiphiles and with the capacity to access, and be maintained in, non-equilibrium for substantial periods of time. The system enables the formation of a robust membrane that displays controlled assembly and disassembly capabilities, adhesion and sealing to surfaces, self-healing and the capability to undergo morphogenesis into tubular structures with high spatiotemporal control. We use advanced microscopy along with turbidity and spectroscopic measurements to investigate the mechanism of assembly and its relation to the distinctive membrane architecture and the resulting dynamic properties. Using cell-culture experiments with endothelial and adipose-derived stem cells, we demonstrate the potential of this system to generate complex bioactive scaffolds for applications such as tissue engineering.

references:
Karla E. Inostroza-Brito, Estelle Collin, Orit Siton-Mendelson, Katherine H. Smith, Amàlia Monge-Marcet, Daniela S. Ferreira, Raúl Pérez Rodríguez, Matilde Alonso, José Carlos Rodríguez-Cabello, Rui L. Reis, Francesc Sagués, Lorenzo Botto, Ronit Bitton, Helena S. Azevedo, Alvaro Mata. Co-assembly, spatiotemporal control and morphogenesis of a hybrid protein–peptide system. Nature Chemistry, 2015; DOI: 10.1038/nchem.2349
related:
Self-assembling material that grows and changes shape could lead to artificial arteries

http://www.kurzweilai.net/self-assembling-material-could-lead-to-artificial-arteries

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A biomimetic dental prosthesis

September 30, 2015

Cross section of an artificial tooth under an electron microscope (pseudocolor). Ceramic platelets are oriented vertically in the enamel and horizontally in the dentin. (credit: Hortense Le Ferrand/ETH Zürich)

A new procedure that can mimic the complex fine structure of biological composite materials, such as teeth or seashells, has been developed by ETH Zurich researchers. It could allow for creating synthetic materials that are as hard and tough as their natural counterparts.

The secret of these hard natural biomaterials is in their unique fine structure: they are composed of different layers in which numerous micro-platelets are joined together, aligned in identical orientation in each layer.

Although methods exist that allow material scientists to imitate nacre (mother of pearl), it was a challenge to create a material that imitates the entire seashell, with comparable properties and structural complexity, according to the researchers, led by André Studart, Professor of Complex Materials.

The new procedure mimics the natural model almost perfectly. It recreates the multiple layers of micro-platelets with identical orientation in each layer in a single complex piece by using a “magnetically assisted slip casting” (MASC) procedure.

How to create a tooth

Here’s how the procedure works:

Create a plaster cast to serve as a mold.
Pour in a suspension containing magnetized ceramic platelets, such as aluminum oxide platelets. The pores of the plaster mold slowly absorb the liquid from the suspension, which causes the material to solidify and to harden from the outside in.
Create an ordered layer-like structure by applying a magnetic field during the casting process, changing its orientation at regular intervals. As long as the material remains liquid, the ceramic platelets align to the magnetic field. In the solidified material, the platelets retain their orientation.
This continuous process can produce multiple layers with differing material properties in a single object and are almost perfect imitations of their natural models, such as nacre or tooth enamel, says Florian Bouville, a post-doc and co-lead author of the study, which is published in the journal Nature Materials. “Our technique is similar to 3-D printing, but 10 times faster and much more cost-effective.”

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The left structure is showing the natural tooth in its gypsum mold. The middle structure is the artificial tooth (sintered but not yet polymer infiltrated). The model on the right has been sintered and polymer infiltrated. It is embedded in a “puck” to enable polishing and coated with platinum to prevent charging in the electron microscope. (credit: Tobias Niebel/ETH Zurich)

To demonstrate the process, Studart’s research group produced an artificial tooth with a microstructure that mimics that of a real tooth. The surface of the artificial tooth is as hard and structurally complex as real tooth enamel, while the layer beneath is as tough as the dentine of the natural model.

They began by creating a plaster cast of a human wisdom tooth. They then filled this mold with a suspension containing aluminum oxide platelets and glass nanoparticles as mortar. Using a magnet, they aligned the platelets perpendicular to the surface of the object. Once the first layer was dry, the scientists poured a second suspension without glass particles into the same mold. The aluminium oxide platelets in the second layer were aligned horizontally to the surface of the tooth using the magnet.

This double-layered structure was then sintered (“fired” in a kiln) at 1,600 degrees C to densify and harden the material. Finally, the researchers filled the pores that remained after the sintering with a synthetic monomer used in dentistry, which subsequently polymerized (formed into a complex material).

Artificial teeth that behave just like the real thing

“The profile of hardness and toughness obtained from the artificial tooth corresponds exactly with that of a natural tooth,” says Studart.

The current study is an initial proof-of-concept, which shows that the natural fine structure of a tooth can be reproduced in the laboratory, he says. “The appearance of the material has to be significantly improved before it can be used for dental prostheses.

He noted that the base substances and the orientation of the platelets can be combined as required, “which rapidly and easily makes a wide range of different material types with varying properties feasible.” For example, copper platelets could be used in place of aluminum oxide platelets, allowing for use in electronics.

One part of the MASC process, the magnetization and orientation of the ceramic platelets, has been patented.

Abstract of Magnetically assisted slip casting of bioinspired heterogeneous composites

Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture.

references:
Hortense Le Ferrand, Florian Bouville, Tobias P. Niebel, André R. Studart. Magnetically assisted slip casting of bioinspired heterogeneous composites. Nature Materials, 2015; DOI: 10.1038/nmat4419
related:
Biomimetic dental prosthesis

http://www.kurzweilai.net/biomimetic-dental-prosthesis

Language about climate change differs between proponents and skeptics

Waterloo – Proponents of climate change tend to use more conservative, tentative language to report on the science behind it, while skeptics use more emotional and assertive language when reinterpreting scientific studies, says research from the University of Waterloo.

Tentative language would include words such as “possible,” “probable” or “might.” The terms “alarmist” and “wrong” are examples of emotional language.

Using a series of computational text analysis tools to measure the use of hedging or emotional words, Srdan Medimorec and Gordon Pennycook, both PhD candidates in the Department of Psychology at Waterloo, examined two recent reports of opposing groups. The Intergovernmental Panel on Climate Change (IPCC) holds that climate change is unequivocal and that humans influence climate, while the Nongovernmental International Panel on Climate Change (NIPCC) is skeptical of the human impact on climate change.

Although the IPCC clearly warns of the threat of climate change, the text analysis showed that their report used more cautious, less explicit language to present their claims. This finding coincides with work indicating that the IPCC has tended to provide overly conservative estimates of the impact of climate change in previous publications. By contrast, the NIPCC report reinterprets the scientific findings with more certain, aggressive language to advance the case that human-made climate change is a myth.

“Given the scientific consensus that climate change represents a real threat, we might expect the IPCC report to exhibit a more assertive style, yet they don’t,” said Medimorec. “This may be because the charged political atmosphere has made climate scientists cautious in their choice of words.”

The study found substantial differences between the IPCC and NIPCC reports despite the fact that they were both intended to be comprehensive assessments of climate science research and each have many authors.

“The language style used by climate change skeptics suggests that the arguments put forth by these groups may be less credible in that they are relatively less focused upon the propagation of evidence and more intent on refuting the opposing perspective,” said Pennycook. “Although there are many factors that determine which words scientists decide to use, the results of our study are consistent with the idea that political context is an important factor for science communication.”

Those who study science communication agree that the nuances in the language may reflect a difference in the function of the two groups.

“When people communicate as advocates, they tend to use more certainty in their language than may be warranted,” said Vanessa Schweizer, a professor with the Department of Knowledge Integration in the Faculty of Environment at Waterloo, and who is also affiliated with its Interdisciplinary Centre on Climate Change. “In contrast, scientists are more tentative when presenting their findings because they don’t want to oversell what can be concluded from the science.”

The two reports the researchers analyzed are “Working Group 1: The Physical Science Basis” by the IPCC and “Climate Change Reconsidered II: Physical Science” by the NIPCC. The Waterloo researchers did not evaluate the accuracy of the reports, which are both available online. The study appears in the peer-reviewed journal Climatic Change.

http://www.exchangemagazine.com/morningpost/2015/week39/Tuesday/15092906.htm

Research Adds to Evidence that Viruses are Alive

CHAMPAIGN, Ill. — A new analysis supports the hypothesis that viruses are living entities that share a long evolutionary history with cells, researchers report. The study offers the first reliable method for tracing viral evolution back to a time when neither viruses nor cells existed in the forms recognized today, the researchers say.

The new findings appear in the journal Science Advances.

Until now, viruses have been difficult to classify, said University of Illinois crop sciences and Carl R. Woese Institute for Genomic Biology professor Gustavo Caetano-Anollés, who led the new analysis with graduate student Arshan Nasir. In its latest report, the International Committee on the Taxonomy of Viruses recognized seven orders of viruses, based on their shapes and sizes, genetic structure and means of reproducing.

“Under this classification, viral families belonging to the same order have likely diverged from a common ancestral virus,” the authors wrote. “However, only 26 (of 104) viral families have been assigned to an order, and the evolutionary relationships of most of them remain unclear.”

Part of the confusion stems from the abundance and diversity of viruses. Less than 4,900 viruses have been identified and sequenced so far, even though scientists estimate there are more than a million viral species. Many viruses are tiny – significantly smaller than bacteria or other microbes – and contain only a handful of genes. Others, like the recently discovered mimiviruses, are huge, with genomes bigger than those of some bacteria.

The new study focused on the vast repertoire of protein structures, called “folds,” that are encoded in the genomes of all cells and viruses. Folds are the structural building blocks of proteins, giving them their complex, three-dimensional shapes. By comparing fold structures across different branches of the tree of life, researchers can reconstruct the evolutionary histories of the folds and of the organisms whose genomes code for them.

The researchers chose to analyze protein folds because the sequences that encode viral genomes are subject to rapid change; their high mutation rates can obscure deep evolutionary signals, Caetano-Anollés said. Protein folds are better markers of ancient events because their three-dimensional structures can be maintained even as the sequences that code for them begin to change.

Today, many viruses – including those that cause disease – take over the protein-building machinery of host cells to make copies of themselves that can then spread to other cells. Viruses often insert their own genetic material into the DNA of their hosts. In fact, the remnants of ancient viral infiltrations are now permanent features of the genomes of most cellular organisms, including humans. This knack for moving genetic material around may be evidence of viruses’ primary role as “spreaders of diversity,” Caetano-Anollés said.

The researchers analyzed all of the known folds in 5,080 organisms representing every branch of the tree of life, including 3,460 viruses. Using advanced bioinformatics methods, they identified 442 protein folds that are shared between cells and viruses, and 66 that are unique to viruses.

Crop sciences and Carl R. Woese Institute for Genomic Biology professor Gustavo Caetano-Anollés led a study that adds to the evidence that viruses are alive and share a long evolutionary history with other life forms.PHOTO CREDIT: L. BRIAN STAUFFER“This tells you that you can build a tree of life, because you’ve found a multitude of features in viruses that have all the properties that cells have,” Caetano-Anollés said. “Viruses also have unique components besides the components that are shared with cells.”

In fact, the analysis revealed genetic sequences in viruses that are unlike anything seen in cells, Caetano-Anollés said. This contradicts one hypothesis that viruses captured all of their genetic material from cells. This and other findings also support the idea that viruses are “creators of novelty,” he said.

Using the protein-fold data available in online databases, Nasir and Caetano-Anollés used computational methods to build trees of life that included viruses.

The data suggest “that viruses originated from multiple ancient cells … and co-existed with the ancestors of modern cells,” the researchers wrote. These ancient cells likely contained segmented RNA genomes, Caetano-Anollés said.

The data also suggest that at some point in their evolutionary history, not long after modern cellular life emerged, most viruses gained the ability to encapsulate themselves in protein coats that protected their genetic payloads, enabling them to spend part of their lifecycle outside of host cells and spread, Caetano-Anollés said. The protein folds that are unique to viruses include those that form these viral “capsids.”

“These capsids became more and more sophisticated with time, allowing viruses to become infectious to cells that had previously resisted them,” Nasir said. “This is the hallmark of parasitism.”

Some scientists have argued that viruses are nonliving entities, bits of DNA and RNA shed by cellular life. They point to the fact that viruses are not able to replicate (reproduce) outside of host cells, and rely on cells’ protein-building machinery to function. But much evidence supports the idea that viruses are not that different from other living entities, Caetano-Anollés said.

“Many organisms require other organisms to live, including bacteria that live inside cells, and fungi that engage in obligate parasitic relationships – they rely on their hosts to complete their lifecycle,” he said. “And this is what viruses do.”

The discovery of the giant mimiviruses in the early 2000s challenged traditional ideas about the nature of viruses, Caetano-Anollés said.

“These giant viruses were not the tiny Ebola virus, which has only seven genes. These are massive in size and massive in genomic repertoire,” he said. “Some are as big physically and with genomes that are as big or bigger than bacteria that are parasitic.”

Some giant viruses also have genes for proteins that are essential to translation, the process by which cells read gene sequences to build proteins, Caetano-Anollés said. The lack of translational machinery in viruses was once cited as a justification for classifying them as nonliving, he said.

“This is no more,” Caetano-Anollés said. “Viruses now merit a place in the tree of life. Obviously, there is much more to viruses than we once thought.”

http://www.labmanager.com/news/2015/09/research-adds-to-evidence-that-viruses-are-alive#.VgrxA6ulYvY

Apple’s 13-million iPhone weekend: What the analysts said (updated)

Excerpts from the notes we saw.

Gene Munster, Piper Jaffray: Opening Weekend iPhone Sales At High End Of Our Expectations. Apple announced this morning that opening weekend iPhone 6S and 6S Plus sales were “more than 13 million units” compared to our expectations of 12-13 million. In 2014, the company sold 10 million units during opening weekend for the iPhone 6 and 6 Plus launch. This year’s launch benefited from the launch in China coinciding with the broader launch. Overall, we see opening weekend results, coupled with our read on sell- through, as a sign that the iPhone 6S cycle is off to a good start and continue to be comfortable with our 3% iPhone 6S cycle unit growth compared to the Street at flat. Overweight. $172.

Daniel Ives, FBR: How About Them Apples? We view 13 million as a “bull case” number from the weekend as bears were saying 10.5 million to 11 million was possible, and this was up significantly from the 10 million units sold in the iPhone 6 first launch weekend, although this is not apples to apples as China pre-sales/launch were not included in the year-ago number. We estimate China sales during the 6s launch weekend of roughly 2 to 2.5 million, driven by exceptionally strong pre-order demand and, thus, means non-China iPhone 6s units were up roughly between 5% and 10% vs. its predecessor, a Lebron-like performance in our opinion given the high water mark set a year ago. With pre-order sales looking particularly strong out of the linchpin China region and a “white hot” launch weekend sales number announced this morning, we believe potential upside to iPhone December numbers should help remove the “China iPhone black cloud” hovering over Apple’s head despite lingering bear chatter on the name. Outperform. $175.

Jim Suva, Citigroup: We believe two factors positively influenced sales this weekend: 1) China’s inclusion this year in the first phase of the launch… 2) Apple’s own iPhone Upgrade program in the US… We believe tough comps and limited potential sales/EPS upside in the near term may cause some investors to exit the stock thereby providing an attractive entry for long term investors. Outperform. $135.

Tony Sacconaghi, Bernstein: Supply is Strong, but How About Demand? While first weekend sales of 13M is strong vs. history, it is important to note that the figure largely reflects available supply of iPhones, rather than underlying demand, and initial supply likely should have been stronger this year vs. last… The real measure of initial demand for a new iPhone is orders – Apple typically reports the number of orders it receives in the first 24 hours, but did not this year – leaving us with little to truly gauge demand relative to previous cycles… On net, we believe that it is hard to conclude from Apple’s first weekend sales whether iPhone 6S will eclipse last year’s CY Q4/FY Q1 level, which remains investors’ principal near-term focus. Outperform. $135.

Abhey Lamba, Mizuho: First Weekend’s Sales Do Not Seem Overwhelmingly Positive. We note that of the 13mm shipped over the weekend, only two days’ sales (Friday and Saturday) will be included in the September quarter as Apple ended its F4Q15 on Sep 26. As such, we think about 5-7mm units from the sales will contribute to the December quarter whereas all of the first weekend’s sales were included in the September quarter last year. Secondly, Apple intends to ship the new phones to ~130 countries by year- end versus 115 last year. As such, we think distribution expansion this year could help the company get past the tough compare for the December quarter but the entire 6s cycle will likely have a tough time competing against tough compares, which could start impacting growth rates starting with the March quarter. Neutral. $125.

Kulbinder Garcha, Credit Suisse: Growing installed base supports growth next year. Our installed base analysis continues to point to iPhone growth ahead. With a record number of users switching to the iOS platform this year, the iPhone installed base has seen strong growth. Additionally, with Apple’s new installment plan, we believe Apple may be able to keep its replacement rate at around 29 months next year, about 1 month faster than its historical rate, giving us confidence that our 234mn/241mn estimate in CY15/CY16 could prove conservative. Outperform. $145.

Keith Bachman, BMO: Record Weekend. Supply appears healthy for iPhone 6s on a global basis, but much more limited for the 6s Plus. Many stores have very limited supply of the iPhone 6s Plus. Apple stores in Japan seem to be sold out of everything… We currently project iPhone units of around 47 million in the September quarter and 72 million in the December quarter, though our September quarter estimate could prove conservative given the record sales in the first weekend. We believe Apple’s new iPhone Upgrade Program will benefit iPhone sales in the long-term including CY2016, but less so in the December quarter given that a large portion of the installed base is still under traditional two-year contracts. Consistent with our past comments, we believe that two-thirds of iPhone sales in CY2016 will be generated from upgrades and one-third from new users. Outperform. $145.

Timothy Arcuri, Cowen: Strong Results, But Less Rosy Than First Look. Following our checks in Asia, we continue to see a downside bias to Street iPhone units in particular for CQ4 and CQ1:16 as our field work supports a build of mid 40MM units for CQ3 and mid-70MM for CQ4, meaning sell-through is likely a little below these levels (see Highlights From Asia Trip and Building Blocks To Continue The Good Life). Moreover, the supply chain has historically seen some upside revision to builds around the launch weekend; this year we have seen no signs of such revisions even going back to our contacts over the weekend. Market perform. $130.

Amit Daryanani, RBC: Will Apple Grow in December? We think YES, as we expect AAPL to ship 75-80M iPhone units in Dec-qtr. A data point that gives us conviction is – the Calendar. Effectively, this year AAPL will have 2 days of iPhone 6s/6s Plus revenues in Sept-qtr (vs. 9 days of new phones last year in Sept-qtr). At minimum given extended lead-times for 6s Plus, this should add 2-2.5M units in Dec-qtr ($2.0B revenue). Net/Net: An incremental positive that enables better compares for Dec-qtr and enable AAPL to exceed investor fears and show iPhone unit sales of 75-80M in Dec-qtr. Outperform. $150.

Ananda Baruah, Brean Capital: Potential For A New iPhone Form-Factor In The Spring. We believe that iPhone “tension” likely lies to the upside for our Dec Q estimate of 72M (we could see as high as 80M). That said, we believe the next true elongated stock “move” will be determined by what CY16 iPhone ships can look like, and the Street likely won’t have a view on that until April when AAPL reports the Mar Q. We continue to believe that Street numbers are materially low through ’17. Fundamentally speaking, we believe AAPL stands to deliver material EPS upside from 1) iPhone shipments through ’17, 2) favorable GM from both iPhones and iPhone mix (more 6 Plus’ than realized), and 3) materially more Opex $ leverage through at least ’16 as AAPL realizes the benefits from the recent iPhone 6 and iWatch investment cycles. Buy. $170.

http://fortune.com/2015/09/29/apple-iphone6s-analysts-update/

Urgent attention needed for seniors’ health care

September 29, 2015

Credit: Flickr
Canada’s population is aging rapidly, with one-quarter of residents expected to be 65 and older by the year 2036. Yet a recent report from B.C.’s seniors advocate says family caregivers are dealing with extremely high levels of stress.

As UBC launches its new Master of Health Leadership and Policy in Seniors Care, Jennifer Baumbusch, associate professor in the UBC School of Nursing, discusses why the health needs of aging adults are in urgent need of attention.

Jennifer Baumbusch

How are the health needs of seniors different from the rest of the population?

Compared to the younger adult population seniors have more complex health-care needs, because they tend to have more chronic diseases. Whenever a senior comes into the health-care system you’re looking at multiple issues. And it’s not just health issues but social, housing and financial issues as well. You have to look across all of those things, which are changing as people age.

We have to shift our thinking away from short-term solutions. We need to be planning to support people as they age over time. Policy makers and leaders need to design services and supports that meet the complex needs of this population.

What can the health-care system do to prepare for those needs?

When I started my nursing career 20 years ago, we were talking about the aging population. It’s a little late to be still talking about “getting ready.” We need to be ready now. We know that there are great evidence-based models for care that exist in the community and hospitals and in residential care. We need to commit to implementing them over the long term.

In particular, we look at our hospitals, which have not been oriented to seniors care at all. We need continuing education for clinicians as well as leaders in that sector; by and large they may not have chosen to work in seniors care but now, by virtue of the population they serve, they’re working in seniors care.

Within our undergraduate programs, where people have an interest in working with different populations, older adults tend to be at the bottom of the list. There’s a real mismatch at times between how people are being trained for health care and who they’re actually going to be caring for.

What type of training is needed?

Health-care providers need to understand that if we have someone who comes in with a broken hip, they may also have dementia, they may also have diabetes, they may also have heart failure, and you need to be keeping all those balls in the air.

It’s also much more important for seniors to maintain their level of activity and their level of function. For an older adult to spend 24 to 48 hours in a hospital bed, there will be a much greater loss of function than with a younger adult.

What can individuals do to prepare themselves or their loved ones for the challenges of aging?

People often say, “I don’t want to end up in a nursing home when I’m old,” but then they don’t really do any realistic planning beyond that. People really need to think about they want their senior years to look like and make a plan. There are all kinds of resources and services that people can access, but they need to think in real terms about what they want, and then communicate that to their family members and their health-care providers.

In particular, they need to have that conversation with their family physicians or nurse practitioners providing primary care. We often hit a crisis and people end up in the ER, and no one knows what this individual wants. At that moment it’s too late to put a different kind of plan in place.

Find other stories about: Jennifer Baumbusch, Master of Health Leadership and Policy in Seniors Care, UBC School of Nursing

http://news.ubc.ca/2015/09/29/urgent-attention-needed-for-seniors-health-care/

Short Walks Can Counteract Negative Effects Of Sitting All Day

Most workplaces are sedentary environments, and most people spend their days using computers or sitting at desks, all of which researchers say is bad for health.

While several previous studies have pointed this out, researchers at the University of Missouri found in a small study that walking for as little as 10 minutes after prolonged periods of sustained sitting can counteract its negative effects on the vascular system.

“It’s easy for all of us to be consumed by work and lose track of time, subjecting ourselves to prolonged periods of inactivity,” said Dr. Jaume Padilla, an assistant professor of nutrition and exercise physiology in the school of medicine at the University of Missouri, in a press release. “However, our study found that when you sit for six straight hours, or the majority of an eight-hour work day, blood flow to your legs is greatly reduced.”

The researchers worked with 11 healthy men, measuring their vascular function before and after a period of prolonged sitting. They found that after 6 continuous hours of sitting, blood flow in the popliteal, an artery in the lower leg, was significantly reduced.

After finding that blood flow was reduced in the the men’s lower leg’s, researchers asked each of them to walk for 10 minutes. The self-paced walking restored the impaired vascular blood flow and improved blood flow.

The researchers acknowledge that reversing the basic sedentary modern lifestyle may not be possible, they plan to conduct further, larger studies to explore whether small bouts of walking can be shown to reverse the effects of all that sitting.

“Studies have shown that sitting less can lead to better metabolic and cardiovascular health,” Padilla said. “However, more research is needed to determine if repeated periods of reduced vascular function with prolonged sitting lead to long-term vascular complications.”

UPI

http://www.updatednews.ca/2015/09/29/short-walks-can-counteract-negative-effects-of-sitting-all-day/