Showing posts with label Medical with Technology. Show all posts
Showing posts with label Medical with Technology. Show all posts

Monday, March 14, 2016

GM mosquitoes could block spread of Zika in Florida



Genetically modified mosquitoes could be released in Florida to block the spread of the Zika virus after the FDA confirmed they would cause "no significant threat to the environment".

The OX513A mosquito -- or Aedes aegypti -- is modified by British bioengineering company Oxitec, and has been approved following evaluation by the FDA on potential health and environmental impacts.

According to Oxitec, OX513A is intended to "suppress the population of that mosquito" at the release site in order to stop the transmission of diseases such as Zika, dengue and yellow fever.

The genetic modification does this by transmitting lethal genes to its offspring, which subsequently die before reaching adulthood. It has already been trialled in Brazil, Panama and the Cayman Islands, and Oxitec claims that these trials reduced the Aedes aegypti population by more than 90 percent.

Similar mosquitoes have been modified to halt the spread of malaria.

The FDA said in a statement that the mosquitos "do not bite humans or other animals", and are therefore "not expected to have any direct impacts on human or animal health".

"The Aedes aegypti mosquito represents a significant threat to human health," said Hadyn Parry, chief executive of Oxitec, in a statement. "In many countries it's been spreading Zika, dengue and chikungunya viruses."

"The mosquito is non-native to the US and difficult to control, with the best available methods only able to reduce the population by up to 50 percent, which is simply not enough," Parry continued. "We look forward to this proposed trial and the potential to protect people from Aedes aegypti and the diseases it spreads."

The FDA will need to make a further decision before the mosquitoes are released into the environment, and will be consulting the public for thirty days before final approval.

Source: http://www.wired.co.uk

Sunday, March 6, 2016

Fingertip surgery



A stretchable electronic sensor may replace the scalpel and other operating room tools for some surgical procedures. It lets physicians feel electronic activity and slice tissue with their fingertips. Futuristicnews.com reports that researchers at the University of Illinois, Northwestern University and Dalian (China) University of Technology changed hard semiconductors into flexible electronics “and managed to produce special materials, which could be used for surgical gloves that give their wearer an enhanced sense of touch.

” The news website states that silicon was transformed into ultrathin “nanomembranes, cut into wavy shapes and combined with a rubbery membrane.”

Source: Futuristicnews.com

A health check chair



Checking health signs such as blood pressure, temperature and mobility usually involves multiple tests and can be time-consuming. A chair developed by Sharp is equipped with multiple sensors that can measure a user’s vital signs all at once and save the data to the cloud for physicians to reference. Sharp designed the chair for patients to use at home and is considering adding a videoconferencing system so patients can visit with physicians remotely.

“Rather than people who are ill going to the doctor, our idea is for healthy people to think about how to stay healthy, prepare for any emergencies and improve their day-to-day lifestyle,” a spokesman said way back in 2013.

Source: www.diginfo.tv

The orderly robot



The UCSF Medical Center at Mission Bay now has a fleet of about two dozen Tug robots delivering drugs, linens and meals and carting away medical waste, soiled linens and trash, reports Josh Valcarcel in Wired magazine. Twenty-seven infrared and ultrasonic sensors enable the robots to avoid bumping into people or blocking their paths.

They stand back from elevators and summon them through the hospital’s Wi-Fi, using radio waves to open doors. Human staff have varied reactions to the Tugs and, in his amusing piece, Valcarcel, who grew up in the Silicon Valley, says even he finds the hospital robots “just weird.”

Source: Wired, February 2015

Battery-powered germ-killers



As the number of joint replacement surgeries grows, so do concerns about the complications of infection from antibiotic-resistant superbugs. Biomedical engineers from the North Carolina State University Department of Industrial and Systems Engineering are developing nanotechnology built directly into orthopedic implants. A battery-activated device powers an army of microscopic germ-killers to fight bacterial infections, including methicillin-resistant Staphyloccus aureus, or MRSA.

The process applies a low-intensity electrical charge to a silver titanium implant, releasing low-toxicity silver ions that kill or neutralize bacteria. The power source, similar to a watch battery, can be integrated into the implant design. The body’s own fluids act as a conducting medium between battery and silver, enabling the low-level charge.

Source: North Carolina State University’s Edward P. Fitts Department of Industrial and Systems Engineering

Press-and-print body parts



Last year, Cornell University scientists used a 3-D printer to produce an artificial ear that, according to Randy Reiland’s January 2014 report in Smithsonian.com, “looks and works like the real thing.” Reiland notes that researchers at the University of Pennsylvania and Massachusetts Institute of Technology have bioprinted blood vessels; their counterparts at Wake Forest University developed a method for printing skin cells directly onto wounds. And a company called Organovo has come up with a 3-D printed liver.

Next up? According to Bernard Meyerson, writing for weforum.com, a 4-D printer is being developed capable of creating products that can alter themselves in response to environmental change, such as heat and humidity. That could be useful for things like clothes and footwear, Meyerson points out, and also for “health care products, such as implants designed to change in the human body.”

Source: Smithsonian.com, Jan. 6, 2014; World Economic Forum, weforum.org, March 4, 2015

Google glass aids trauma care



Trauma surgeons at the Forbes Hospital Trauma Center near Pittsburgh are testing Google Glass technology using a software called VIZR, Visual Info Zonal Reminder. Google Glass is a wearable technology with an optical head-mounted display that provides information in a smartphone-like, hands-free format. Wearers communicate with the Internet via natural language voice command. At Forbes, the technology initially is being used to provide prompts during patient resuscitation based on checklists similar to those used in the aviation industry.

“With this new technology, surgeons will have hands-free, immediate access to critical information, checklists and reminders specific to injury categories that will greatly assist our efforts to provide effective, timely care that saves lives,” says Christoph R. Kaufmann, M.D., trauma medical director. For example, if a pregnant patient with injuries to the abdomen is in transport to the emergency department, the surgeon can use a voice command to access a checklist with crucial questions to ask the paramedic upon or even before the ambulance arrives.

Source: Allegheny Health Network

The Medical Technologies That Are Changing Health Care



New, eye-popping medical technology provides earlier diagnoses, personalized treatments and a breathtaking range of other benefits for both patients and health care professionals.

Not long ago, people started wearing wristbands that recorded the number of steps they took, their heart rates and sleep cycles. But if the now-ubiquitous bands and accompanying apps that stored biorhythms started out as novelties, they paved the way for a new generation of gadgets that have become serious tools to improve health care delivery and outcomes. These newfangled contraptions will change how and where care is delivered and will enable providers to stay continuously connected with patients wherever they may be — or at least connected to the devices that indicate whether a patient is abiding by prescription protocols, getting up and about safely, and eating regularly. In some cases, they may even provide an early-warning system for serious degenerative conditions like Alzheimer’s and Parkinson’s disease.

The scope of these emerging technologies is breathtaking. High-tech sensors soon will monitor the at-home cardiac patient’s heart every minute of every day. A new type of chip, embedded in a pill will be activated at the precise moment it reaches a patient’s stomach, and will confirm for the medical record that he’s taking his medications. Straight out of science fiction, new gizmos will emerge that can scan a body for a host of symptoms without poking or prodding and, in seconds, they’ll make a diagnosis.

They may sound futuristic, but many of these devices already exist and, in fact, are being supplanted by a new generation of products that do it all faster and better.

For instance, wearable techno patches now can monitor a person’s heart rate, body temperature and other vital signs — a big leap over monitors that have to be hooked up — and their results read by the patient. The data are more robust and valuable because the patches provide “continuous monitoring instead of taking a periodic snapshot,” says Sean Chai, director of innovation and advanced technology services at Kaiser Permanente.

Another sensor under development will be capable of reading biomarkers, blood-borne chemical clues that signal the levels of stress and anxiety, which can affect health as much as disease, diet and daily activity do. If the stress-level data can be synchronized with vitals such as pulse and blood pressure, a patient will receive personalized feedback on what makes her tense and which relaxation techniques work for her. Steven Steinhubl, M.D., who directs the digital medicine program at Scripps Translational Science Institute, San Diego, calls this aid to stress control “the most exciting aspect of wearables, and I’m convinced it will happen. There are a lot of hurdles to overcome before it becomes extremely functional, but the capability is remarkable.”

Menu of innovation

Pick a medical issue — congestive heart failure, diabetes, medication noncompliance, even stressful isolation — and you’ll find researchers working to solve it with remarkable new technologies. Here are some areas they’re targeting:

Heart failure

This is Medicare’s most costly diagnosis, and the mortality rate is comparable to a new cancer diagnosis. The Scripps institute is testing three types of sensors — necklace, wristband and watch — that give both the patient and the care team continuous information on how a compromised heart is functioning. Medications can be adjusted and dietary recommendations can be made in real time that are specific to the individual. The sensors replace once-daily routines such as measuring a patient’s weight for signs of water retention, an indirect rather than direct measure of heart function.

Social influences

The ability to track a patient’s movements will help providers determine how social and environmental factors affect his or her health. The Kaiser institute is evaluating products that can analyze various components of a patient’s daily routine. Where does she eat breakfast and lunch? Does he interact with other people on a regular basis, or is he generally isolated? Correlating such personal information with vital signs can produce important insights into an individual’s well-being.

Medication compliance

An ingestible — and digestible — sensor is being rolled out to record whether and when a patient takes a medication. Developed by Proteus Digital Health, London and Redwood City, Calif., the chip uses gastric fluids as a power source, which means it turns on when it reaches the stomach. The sensor transmits the identity of the medication and the time it was taken to a skin patch, which then sends that info to an app on the patient’s mobile device. The patch also detects and transmits heart rate, activity and rest.

Timely diagnosis

Diagnostic tests to detect medical problems can be expensive and time-consuming for patients, and they have to be done one by one. A nonprofit organization called the XPrize Foundation is holding a $10 million competition to find a solution. Early next year, it will choose among 10 teams of finalists from around the world who are attempting to create a “tricorder,” named for the fictional device used to diagnose ailing characters in the “Star Trek” TV series.

Approaches vary among the competing teams but, at minimum, all devices are required to continuously monitor up to five vital signs for 72 hours, says Grant Campany, the foundation’s senior director. And they must be able to identify and diagnose up to 15 conditions as varied as stroke, AIDS, pertussis and chronic obstructive pulmonary disease.

3-D printing

Every geek’s jaw dropped at the sight of the 3-D printer when it first came to market. These days, medical researchers are harnessing its potential to vastly improve patient care. For example, Kaiser Permanente’s Los Angeles Medical Center is perfecting the use of 3-D printers to produce exact, multidimensional models of trouble spots inside patients. Surgeons can scrutinize and handle the models, then simulate a variety of possible procedures before ever going into the operating room.

This technology’s potential was dramatically demonstrated when a Kaiser patient suffered a tear in the wall of his aorta, the main artery leading out of his heart. The clinical team “printed his artery in 3-D and actually went through several different scenarios on how they could insert a stent to prevent further rupture,” Chai says. “They used that in a team-based training environment to see how they could confidently proceed with some of these special procedures.” Chai compares the process with a flight simulator in which a pilot masters the intricacies of the cockpit before entering a real one. The innovation “allows us to develop a more specialized, personalized, precise treatment plan,” Chai explains. “Ultimately, that improves the quality and affordability of care.” The patient, by the way, came through the procedure fine and is recovering.

The potential and how to reach it

Much of the emerging technology is aimed at getting inside the body without actually going inside it. “There is already significant interest in noninvasive data acquisition, whether that’s light imaging or infrared or sound waves,” says Peter Reinhart, director of the Institute for Applied Life Sciences, University of Massachusetts, Amherst.

Longer-range research is focused on capturing much more sophisticated information than current products can, Reinhart says. A promising example is a patch that uses a combination of electrical and chemical signals to identify either the predisposition to or the existence of a particular disease.

That would provide an enormous advantage when it comes to illnesses that involve brain and nerve degeneration, such as Alzheimer’s, Huntington’s or Parkinson’s disease. Instead of conducting a test and comparing results with a norm, as is done today, continuous tracking of certain biomarkers would establish a personal baseline while an individual is still healthy. Readings that significantly move off the baseline would signal declining cognitive activity before symptoms ever arise, and physicians would be alerted to do further tests. “Now you get a much earlier readout that something has just changed in your body, so let’s talk to someone,” Reinhart says.

To reach that potential, three things must happen: improvements in sensor technology; better interpretation of massive amounts of data in a medically relevant, rigorous way; and development of earlier intervention strategies. “As we get better and better at this, we’re going to find that new therapeutic options are going to be open to us,” Reinhart says. “Identifying an Alzheimer’s patient at the [observable] behavioral point, when 70 percent of the brain mass has already disappeared, really limits the number of therapeutic options you can provide that patient. If you could identify someone like that seven or eight years earlier, it now opens up a very different array of intervention strategies.”

The promise of personalized medicine to meet the unique needs of individuals depends on establishing baselines for each patient. To assess anxiety, for example, “One person’s stressor is another person’s idea of just an average day,” Reinhart says. “So just differentiating across individuals will be huge.”

That’s especially true with post-traumatic stress disorder. A lot of treatments have been shown to be effective, but they work differently for different people, says the Scripps institute’s Steinhubl. The emerging sensors will provide objective evidence of when someone is getting anxious, and how activities like meditating, reading a book, taking a walk or shooting baskets can ease the anxiety. “That can and will be life-changing,” he says. — John Morrissey is a freelance writer in Chicago.

Source: http://www.sciencedaily.com

Monday, February 29, 2016

'IVF chip' helps capture images of sperm fusing with egg

Every mammal on this planet starts in the same way: a sperm encounters an egg and fuses with it. This process is familiar to every eighth grade biology student, and pictures of the event can be found in every biology text book. However, despite this ubiquity, the detailed mechanics of the process itself is still somewhat of a mystery

Now, new techniques - featuring an "IVF chip" - presented recently at the Biophysical Society's 60th annual meeting in Los Angeles, CA, promise to reveal new insights into how a single sperm cell fuses with an egg cell.

The researchers hope the new techniques will help us better understand the causes of infertility and improve treatments.

At the meeting, Benjamin Ravaux, a physics graduate student at the Ecole Normale Supérieure de Paris in France, described how, using the "completely new approach," he and his colleagues captured high-resolution images of the events that unfold at the membrane of the egg cell during mammalian fertilization.

Ravaux says the "IVF chip" is a "unique tool to observe the cascade of molecular and membrane events occurring during the fertilization process," under conditions that mimic what happens in nature.

The idea and design of the device are the product of expertise in biophysics and fertilization and assisted reproduction technologies (ART) - including in vitro fertilization (IVF).

At the heart of the new approach is an "IVF chip" - a microfluidic device made from an electronic chip comprising several layers of silicon polymer sealed on a glass slide.

The design of the chip allows a sperm cell to be held in the bottom layer with an egg cell held above it, inside an "egg cup." At the bottom of the egg cup is a tiny opening, with a width of about 30 microns (roughly half the width of human hair).

Images of fertilization 'as it occurs'

When inserted in the lower layer of the chip, a sperm cell swims through the opening and fuses with the egg held in the egg cup.

The chip is compatible with confocal microscopy and other imaging systems, allowing the researchers to capture high-resolution images and movies of the fertilization process as it occurs.

The images show what happens to the sperm cell when it encounters the membrane of the egg cell. They show the two cells merging their membranes over time and the sperm cell gradually sinking into the egg cell.

The scientists also saw how the DNA in the sperm was assimilated into the egg's cytoplasm - the fluid surrounding the nucleus of the egg cell.

Ravaux explains that the new technique offers scientists the chance to investigate an area of reproductive biology that has remained largely unexplored due to lack of tools.

The IVF chip is different to what has been tried before because it allows scientists to observe what happens when just one sperm cell fuses with an egg. Other attempts to do this have had to settle with observing multiple sperm cells coming into contact with the membrane of the egg cell.

Ravaux says the technique could be combined with other approaches - such as fluorescent antibodies or genetically modified animals - to offer new insights into the membrane events of the sperm-meets-egg process. He concludes:
"An enhanced understanding of the molecular and physical mechanisms responsible for fertilization could ultimately lead to better methods to diagnose the causes of infertility, and improved personalized medicine treatments."


From a study published recently, Medical News Today learned how scientists in China have created functioning sperm from stem cells, raising hope that the approach may one day be used to treat male infertility.

Easy to Use Navik 3D Cardiac Mapping System Cleared in U.S.



APN Health, a firm based in Wisconsin, got hold of an FDA clearance to introduce its Navik 3D cardiac mapping system in the U.S. The system provides live tracking of catheters in 3D gathered from fluoroscopic 2D images, and combines that with the electrical cardiac signals to create volumetric maps of the heart.

The system uses existing fluoroscopes and ECG that are available in cath labs already, and so is the only cardiac mapping system on the market that does not rely on specialty equipment to interface with the patient.

The Navik 3D comes with its own display interface plus an iPad that can be carried around the cath lab that also displays the same available imagery including anatomical maps, cardiac electrical activation maps, and cardiac voltage maps.



http://www.medgadget.com

New Flexible Electronic Films for Body-Worn Medical Devices



At the École polytechnique fédérale de Lausanne, Switzerland researchers have created a new method for making stretchable electronics that may end up being integrated into wearables and medical devices. The prototype films can stretch up to four times their original shape and relax back without suffering any degradation in its electrical properties.

The researchers’ main achievement was achieving in making very narrow wires out of liquid metal (gold/gallium alloy) that bend along with the rest of the film but do not break down into individual pieces.. They’re only a few nanometers in width, and so can be used to connect multiple components within a single larger flexible device.

Here’s more about the new stretchable electronic films:



http://www.medgadget.com

Sunday, February 28, 2016

Medtronic’s CRT-Ds Now Approved for 3 Tesla Scanning in Europe

Medtronic won European CE Mark approval for a number of its cardiac resynchronization therapy defibrillators (CRT-Ds) to be safe for use under MRI imaging of up to 3 Tesla. The approved devices include the Claria MRI Quad CRT-D SureScan, Amplia MRI Quad CRT-D SureScan, and Compia MRI Quad CRT-D SureScan pacers. Additionally, all previously approved MRI-conditional cardiac implants now have a green light to be used in 3T magnetic resonance scanners in Europe.

All three devices use the firm’s Attain Perfoma MRI SureScan Quadripolar leads that come in three shapes to fit different patients, include steroid on the electrodes, and have short bipolar spacing that helps ameliorate phrenic nerve stimulation

Source: http://newsroom.medtronic.com

FDA Approves New ScandiDos System That Measures XRT Dose



When radiation treatment is delivered by a medical accelerator, the amount of exposure that is actually absorbed by the patient has been estimated based on dosage administered and other parameters. The Delta4 Discover, a product from ScandiDos, a Swedish firm, has received FDA clearance to be used to accurately measure the amount of radiation that moves past the patient and calculate the amount that’s actually absorbed.

The system allows for immediate verification of dosage delivered in a fairly non-intrusive way, letting techs go about the procedures pretty much as they normally would while knowing that the required therapy is being absorbed.

The detector simply sits on the receiving end of the radiation beam, past the patient, and counts the number of particles that strike it.

Here’s a promo video for the Delta4 Discover:


Source: http://www.medgadget.com

Automatic Suturing by Robotic Surgical System



At Case Western Reserve University engineers are working on integrating autonomous suturing abilities into the da Vinci robotically-assisted surgical system from Intuitive Surgical. The team managed to purchase a used da Vinci on eBay and are now developing autonomous algorithms to control the device while doing routine suturing. Here’s a couple of the team members presenting their project:


Source: http://www.medgadget.com

Top 5 Medical Technology Innovations



Against the backdrop of health care reform and a controversial medical device tax, medical technology companies are focusing more than ever on products that deliver cheaper, faster, more efficient patient care. They are also making inroads with U.S. Food & Drug Administration regulators to re-engineer the complex review and approval process for new medical devices.

Many in the industry have long felt overly burdened by what they consider to be an unnecessarily complex approval process. Critics claim it impedes innovation and delays the availability of better health care. To change that perception, the FDA last year announced a new Medical Device Innovation Consortium (MDIC) charged with simplifying the process of designing and testing new technologies. With input from industry, government, and other nonprofit organizations, public-private MDIC will prioritize the regulatory science needs of the medical device community and fund projects to streamline the process.

"By sharing and leveraging resources, MDIC may help industry to be better equipped to bring safe and effective medical devices to market more quickly and at a lower cost," says Jeffrey Shuren, M.D., J.D., director of the FDA's Center for Devices and Radiological Health.

As the regulators, politicians, and corporate executives hash out these details, industry engineers and scientists continue to push through new ideas for improving and managing human health. Every year, industry observers like the Cleveland Clinic and the medical device trade press single out their favorite technology trends. These thought leaders agree that today's best technologies strike a balance between reducing the overall cost of medical care and increasing safety and survival rates—and isn't that what health care reform is all about?

Here are five emerging technologies to watch in the year ahead.

1. Cutting Back on Melanoma Biopsies

With the most deadly form of skin cancer, melanoma, a huge number of dangerous-looking moles are actually harmless, but has always been impossible to know for sure without an invasive surgical biopsy. Today dermatologists have new help in making the right call — a handheld tool approved by the FDA for multispectral analysis of tissue morphology. The MelaFind optical scanner is not for definitive diagnosis but rather to provide additional information a doctor can use in determining whether or not to order a biopsy. The goal is to reduce the number of patients left with unnecessary biopsy scars, with the added benefit of eliminating the cost of unnecessary procedures. The MelaFind technology (MELA Sciences, Irvington, NY) uses missile navigation technologies originally paid for the Department of Defense to optically scan the surface of a suspicious lesion at 10 electromagnetic wavelengths. The collected signals are processed using heavy-duty algorithms and matched against a registry of 10,000 digital images of melanoma and skin disease.

2. Electronic Aspirin

For people who suffer from migraines, cluster headaches, and other causes of chronic, excruciating head or facial pain, the "take two aspirins and call me in the morning" method is useless. Doctors have long associated the most severe, chronic forms of headache with the sphenopalatine ganglion (SPG), a facial nerve bundle, but haven't yet found a treatment that works on the SPG long-term. A technology under clinical investigation at Autonomic Technologies, Inc., (Redwood City, CA) is a patient-powered tool for blocking SPG signals at the first sign of a headache. The system involves the permanent implant of a small nerve stimulating device in the upper gum on the side of the head normally affected by headache. The lead tip of the implant connects with the SPG bundle, and when a patient senses the onset of a headache, he or she places a handheld remote controller on the cheek nearest the implant. The resulting signals stimulate the SPG nerves and block the pain-causing neurotransmitters.

3. Needle-Free Diabetes Care

Diabetes self-care is a pain—literally. It brings the constant need to draw blood for glucose testing, the need for daily insulin shots and the heightened risk of infection from all that poking. Continuous glucose monitors and insulin pumps are today's best options for automating most of the complicated daily process of blood sugar management – but they don't completely remove the need for skin pricks and shots. But there's new skin in this game. Echo Therapeutics (Philadelphia, PA) is developing technologies that would replace the poke with a patch. The company is working on a transdermal biosensor that reads blood analytes through the skin without drawing blood. The technology involves a handheld electric-toothbrush-like device that removes just enough top-layer skin cells to put the patient's blood chemistry within signal range of a patch-borne biosensor. The sensor collects one reading per minute and sends the data wirelessly to a remote monitor, triggering audible alarms when levels go out of the patient's optimal range and tracking glucose levels over time.

4. Robotic Check-Ups

A pillar of health reform is improving access to the best health care for more people. Technology is a cost-effective and increasingly potent means to connect clinics in the vast and medically underserved rural regions of the United States with big city medical centers and their specialists. Telemedicine is well established as a tool for triage and assessment in emergencies, but new medical robots go one step further—they can now patrol hospital hallways on more routine rounds, checking on patients in different rooms and managing their individual charts and vital signs without direct human intervention. The RP-VITA Remote Presence Robot produced jointly by iRobot Corp. and InTouch Health is the first such autonomous navigation remote-presence robot to receive FDA clearance for hospital use. The device is a mobile cart with a two-way video screen and medical monitoring equipment, programmed to maneuver through the busy halls of a hospital.

5. A Valve Job with Heart

The Sapien transcatheter aortic valve is a life-saving alternative to open-heart surgery for patients who need new a new valve but can't endure the rigors of the operation. Manufactured by Edwards Life Sciences (Irvine, CA), the Sapien has been available in Europe for some time but is only now finding its first use in U.S. heart centers—where it is limited only to the frailest patients thus far. The Sapien valve is guided through the femoral artery by catheter from a small incision near the grown or rib cage. The valve material is made of bovine tissue attached to a stainless-steel stent, which is expanded by inflating a small balloon when correctly placed in the valve space. A simpler procedure that promises dramatically shorter hospitalizations is bound to have a positive effect on the cost of care.

Source: https://www.asme.org

Scientists improve DNA technology for detecting, treating disease



One of the drawbacks of DNA aptamers - synthetic small molecules that show promise for detecting and treating cancer and other diseases - is they do not bind readily to their targets and are easily digested by enzymes in the body. Now, scientists have found a way to produce DNA aptamers without these disadvantages.

The team - from the Institute of Bioengineering and Nanotechnology (IBN) at Agency for Science, Technology and Research (A*STAR) in Singapore - describes how they developed and tested the improved DNA technology in the journal Scientific Reports.

IBN Executive Director Prof. Jackie Y. Ying says the team created "a DNA aptamer with strong binding ability and stability with superior efficacy," and:

"We hope to use our DNA aptamers as the platform technology for diagnostics and new drug development."

Aptamers are a special class of synthetic ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) molecules that are showing promise for clinical use.

These small molecules could be ideal for drug applications because they can be made for highly specific targets - such as proteins, viruses, bacteria and cells.

Drawbacks of current DNA aptamers

Once aptamers are engineered for a specific target, they bind to it and block its activity.

They are the chemical equivalent of antibodies, except, unlike the antibodies currently used in drug development, they do not cause undesirable immune responses and could be easier to mass produce at high quality.

The first aptamer-based drug - an RNA aptamer for the treatment of age-related macular degeneration (AMD) - was approved in the US in 2004, and several other aptamers are currently being evaluated in clinical trials.

However, no DNA aptamer has yet been approved for clinical use because the ones currently developed do not bind well to molecular targets and are easily digested in the bloodstream by enzymes called nucleases.

In their paper, lead author Dr. Ichiro Hirao, a principal research scientist at IBN, and colleagues describe how they overcame these two problems.

'Unnatural base' and 'mini-hairpin' remove DNA aptamer disadvantages

To overcome the problem of weak binding, the team added a new artificial component - called an "unnatural base" - to a standard DNA aptamer, which typically has four components.

The paper describes how the addition of a fifth unnatural base component to the DNA aptamer strengthened its binding ability by 100 times.

To prevent the aptamer from being easily digested by enzymes, the team added a small piece of DNA that they call a "mini-hairpin DNA."

Dr. Hirao says mini-hairpin DNAs are made of small DNA fragments that form a compact, stem-loop structure, like a hairpin, and this is what makes them stable.

Typically, DNA aptamers do not last longer than an hour in blood at room temperature because they are broken down by nucleases. But the team found the addition of the mini-hairpin DNA could help DNA aptamers survive for days - making them more appealing for drug development.

In their paper, the scientists describe how their modifications improved a DNA aptamer that targets a cell-signaling protein called interferon gamma.

Lab tests showed the improved aptamer survived in human blood at 37 °C after 3 days and "sustainably inhibited the biological activity" of interferon gamma, note the authors.

Dr. Hirao says their modifications show it is possible to generate DNA aptamers with great promise for clinical use: they are potentially more effective in their action, cheaper to produce and have fewer adverse side effects than conventional methods. He concludes:
"The next step of our research is to use the aptamers to detect and deactivate target molecules and cells that cause infectious diseases, such as dengue, malaria and methicillin-resistant Staphylococcus aureus (MRSA), as well as cancer."
In December 2015, Medical News Today learned how researchers from the University of Texas at Arlington are developing a way to detect cancer cells using electronic chips coated with RNA aptamers. The team hopes it will lead to a tabletop tool that offers doctors cheaper and faster tests for disease prediction. Source: http://www.medicalnewstoday.com

Heart Disease Detection Goes High Tech


Experts review the latest techniques that reveal whether you have heart disease

When former President Bill Clinton was diagnosed with heart disease and underwent a quadruple bypass operation to clear his blocked heart arteries in 2004, some Americans panicked and opted to undergo all sorts of tests to find out if they, too, had heart disease.

This hysteria -- and call to arms -- has been dubbed the "Bill Clinton Effect." More than two years after he underwent surgery, cardiologists now have even better high-tech tests enabling them to diagnose heart disease earlier -- with pinpoint precision. And more tests are being investigated.

"Ten to 15 years ago, industry and academia alike identified cardiovascular disease [CVD] as a disease to be tackled," says Stanley l. Hazen, MD, PhD. Hazen is section head of preventive cardiology and cardiac rehabilitation at The Cleveland Clinic in Ohio. "The boon of this research has yet to be materialized, but there are an extensive number of compounds and screening methods in the pike that look promising and attractive."

From blood tests to advances in imaging, here are a few highlights in heart disease detection.

Blood Markers

When you ask your doctor if you have heart disease, he assesses the likelihood based on risk factors. Some key risk factors are age, smoking, diabetes, being male, high blood pressure, and cholesterol. But studies have shown that almost half of the people who suffer coronary events have only two risk factors: being male and over 65. So it is very exciting when new tests come along that can help identify people before they have an event such as a heart attack.

In terms of blood markers, Hazen says that "the mainstay for assessing heart disease risk is low density lipoprotein ['bad'] cholesterol testing". But while we know that LDL plays a major role in determining heart disease, the relationship between severity and the timing of the disease is "incredibly poor. There is much room for improvement," says Hazen.

Checking for C-Reactive Protein

In terms of blood-based screening tests, doctors are increasingly looking at levels of C-reactive protein (CRP), which is an inflammatory marker found in the blood. Several studies have shown that increased concentrations of CRP appear to be associated with increased risk for coronary heart disease, sudden death, and peripheral arterial disease. Inflammation is increasingly being viewed as a major risk factor for heart disease.

"This test is recommended by the American Heart Association and the federal Centers for Disease Control and Prevention," Hazen says. "If it's used as a routine screen in intermediate-risk subjects, it's an even stronger predictor of cardiovascular disease risk than LDL," he tells WebMD. While CRP levels are not specific to the heart, "in terms of risk prediction, it's equal to or better than cholesterol," he says. "More and more we will be seeing an increase in the use of CRP as an adjunct to risk stratification."

CT Scanning

And these are some of the reasons that there is so much enthusiasm for the 64-slice computerized tomography (CT) scan. With this test, doctors can determine if there is calcium buildup in the heart arteries. While older multislice CT scans only allowed visualization of smaller parts of the heart, the 64-slice CT lets doctors visualize more. And computer processing yields a three-dimensional image of the arteries. This procedure eliminates the risk and discomfort associated with traditional angiograms, but there are the usual risks associated with exposure to X-radiation.

Magnetic Imaging

Another test for which both White and Fletcher see a bigger role in the future is magnetic resonance imaging (MRI) of the heart. According to Fletcher, MRI is more accurate than CT scanning. Although MRI is more difficult to perform and more expensive than CT scanning, he predicts that it will have an even bigger role in the future in detecting heart disease.

Other tests available to doctors include intravascular ultrasound (IVUS), a catheter-based technique, which provides real-time, high-resolution images of the heart and its arteries. "The images are in four distinct colors to tell what kind of plaque is there," Diethrich says. "We think that it is going to be very important because plaques differ a great deal. Some cause trouble and other plaques do not."

IVUS "is very good and accurate," says Fletcher. He also envisions a growing role for magnetic resonance angiogram (MRA). MRA is a noninvasive imaging test that uses a powerful magnet and radio waves to provide detailed images of the coronary arteries in less than one hour. "It's less invasive than catheterization," he tells WebMD.

Source: http://www.webmd.com