Publisher Health

A modified ketogenic diet may be worth exploring for people with brain tumors, according to a new study published in the July 7, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology. The diet is high in fat and low in carbohydrates.
The small study found that the diet was safe and feasible for people with brain tumors called astrocytomas. All of the people had completed radiation treatment and chemotherapy. The diet led to changes in the metabolism in the body and the brain. The study was not designed to determine whether the diet could slow down tumor growth or improve survival.
“There are not a lot of effective treatments for these types of brain tumors, and survival rates are low, so any new advances are very welcome,” said study author Roy E. Strowd, MD, MS, MEd, of Wake Forest School of Medicine in Winston-Salem, N.C., and a Fellow of the American Academy of Neurology.
“These cancer cells rely on glucose, or sugar, to divide and grow. Since the ketogenic diet is low in sugar, the body changes what it uses for energy — instead of carbohydrates, it uses what are called ketones. Normal brain cells can survive on ketones, but the theory is that cancer cells cannot use ketones for energy.”
The study involved 25 people with astrocytomas. They followed a type of ketogenic diet, the modified Atkins diet with intermittent fasting, for eight weeks. The diet includes foods such as bacon, eggs, heavy cream, butter, leafy green vegetables and fish. Participants met with a dietician at the start of the study and then every two weeks. Five days a week they followed the modified Atkins diet, which combined carbohydrate restriction with high amounts of fats. Two days a week they fasted, eating up to 20% of their recommended daily calorie amount.
The main goal of the study was to see if people were able to follow the diet with no serious side effects. A total of 21 people completed the study, and 48% followed the diet completely, according to their food records. But urine tests showed that 80% of the people reached the level where their body was primarily using fats and protein for fuel, rather than carbohydrates.
The diet was well-tolerated. Two people had serious side effects during the study — one was not related to the diet and one was possibly related.
By the end of the study, changes in the metabolism in the body and the brain were seen. Hemoglobin A1c levels, insulin levels, and fat body mass all decreased. Lean body mass increased. Specialized brain scans that detect changes in brain metabolites showed an increase in concentrations of ketones and metabolic changes in the tumor.
“Of course more studies are needed to determine whether this diet can prevent the growth of brain tumors and help people live longer, but these results show that the diet can be safe for people with brain tumors and successfully produce changes in the metabolism of the body and the brain,” Strowd said.
A limitation of the study is that study team members provided a high amount of contact with participants, which may not be feasible in a larger study or in routine clinical care.
The study was supported by the philanthropy of Dr. John and Elaine Freeman, Dr. Jon Weingart, the Martz, Redwood and Dalos families, the National Center for Advancing Translational Sciences, National Institutes of Health and National Cancer Institutes.
Story Source:
Materials provided by American Academy of Neurology. Note: Content may be edited for style and length.

You dash into a convenience store for a quick snack, spot an apple and reach for a candy bar instead. Poor self-control may not be the only factor behind your choice, new research suggests. That’s because our brains process taste information first, before factoring in health information, according to new research from Duke University.
“We spend billions of dollars every year on diet products, yet most people fail when they attempt to diet,” said study co-author Scott Huettel, a professor of psychology and neuroscience at Duke. “Taste seems to have an advantage that sets us up for failure.”
“For many individuals, health information enters the decision process too late (relative to taste information) to drive choices toward the healthier option.”
The new paper, which appears July 5 in Nature Human Behaviour, describes the advantage taste has over healthfulness in the decision-making process.
“We’ve always assumed people make unhealthy choices because that’s their preference or because they aren’t good at self-control,” said study co-author Nicolette Sullivan. “It turns out it’s not just a matter of self-control. Health is slower for your brain to estimate — it takes longer for you to include that information into the process of choosing between options.”
The research was undertaken when Sullivan was a postdoctoral associate at Duke. She is now an assistant professor of marketing at the London School of Economics and Political Science.

In what turned out to be one of the most important accidents of all time, Scottish bacteriologist Alexander Fleming returned to his laboratory after a vacation in 1928 to find a clear zone surrounding a piece of mold that had infiltrated a petri dish full of Staphylococcus aureus (S. aureus), a common skin bacterium he was growing.
That region of no bacterial growth was the unplanned birth of a medical miracle, penicillin, and would lead to the era of antibiotics. Now, in a paper published today in the journal Science Translational Medicine, researchers at Johns Hopkins Medicine have announced another accidentally discovered, potentially game-changing treatment — one that may one day provide an alternative immune-based solution to the danger of antibiotic-resistant bacterial infections.
And like Fleming’s surprise finding, the bacterium of note is once again S. aureus — but this time, methicillin-resistant Staphylococcus aureus, the life-threatening strain unharmed by methicillin and other antibiotics, and better known by its acronym, MRSA.
The paper’s senior author, Lloyd Miller, M.D., Ph.D., former professor of dermatology, infectious diseases and orthopaedic surgery at the Johns Hopkins University School of Medicine, and now with Janssen Research and Development, says the research team was originally intending to study the mechanisms behind MRSA skin infections in mice with and without the ability to manufacture interleukin-1 beta (IL-1β). This protein, transformed into its active form by enzymes called caspases, enhances protective immunity by helping immune cells called neutrophils, monocytes and macrophages fight bacterial infections.
“We gave the mice a blocker of all caspases [pancaspase inhibitor], a compound known as Q-VD-OPH, thinking it would leave both sets of mice more vulnerable to MRSA infection,” Miller says. “To our surprise, blocking caspases had the opposite effect, resulting in a rapid and remarkable clearing of the MRSA bacteria by keeping the immune cells alive and boosting their protective function.”
Sensing they might have accidentally uncovered a means of fighting bacterial “superbugs,” Miller and his colleagues conducted their latest study to confirm the unexpected finding was not a fluke.

As the COVID-19 pandemic wanes in the U.S., a new study from the University of Maryland School of Medicine (UMSOM) and University of Maryland Medical Center (UMMC) finds that hospitals nationwide may not be adequately prepared for the next pandemic. A 10-year analysis of hospitals’ preparedness for pandemics and other mass casualty events found only marginal improvements in a measurement to assess preparedness during the years leading up to the COVID-19 pandemic. The study was published last month in the Journal of Healthcare Management.
“Our work links objective healthcare data to a hospital score that assesses the ability to save lives in a disaster,” said study lead author David Marcozzi, MD, Professor of Emergency Medicine at UMSOM and Chief Clinical Officer/Senior Vice President at UMMC. “It attempts to fill a glaring gap in the national conversation on the need for improved assessments of and the opportunity for better hospital planning to assure readiness.”
To conduct the research, Dr. Marcozzi, who is also the COVID-19 Incident Commander for the University of Maryland Medical System, and his colleagues first developed and published a surge index tool that linked standard reported hospital information to healthcare preparedness elements. The tool, called the Hospital Medical Surge Preparedness Index (HMSPI), used data from 2005 to 2014 to produce a score designed to predict how well a hospital can handle a sudden influx in patients due to a mass shooting or infectious disease outbreak. Such data included the size of the medical staff, the number of hospital beds, and the amount of equipment and supplies.
Medical surge capacity is an important measure to assess a hospital’s ability to expand quickly beyond normal services to meet an increased demand for healthcare. The Las Vegas mass shooting in 2017, for example, sent more than 500 concertgoers to local hospitals. During the early weeks of the COVID-19 pandemic, New York City hospitals were under siege with 4,000 patients hospitalized. To calculate the HMSPI, researchers input data from four important metrics: Staff: Doctors, nurses, pharmacists, respiratory technicians and others Supplies: Personal protective equipment, cardiac monitors, sterile bandages, and ventilators Space: Total beds and number of beds that current staff can handle Systems: Framework for enabling electronic sharing of files and information between departments and multiple hospitalsIn the new study, Dr. Marcozzi and his colleagues used data from the American Hospital Association’s annual surveys of more than 6,200 hospitals nationwide that were collected from 2005 to 2014. They also employed data from the U.S. Census Bureau to determine population estimates in cities and the Dartmouth Atlas Project to establish the geographic service area of each hospital. They combined the hospital metrics gleaned from the AHA’s annual surveys with the geographic data to calculate HMSPI composite scores for hospitals in each state.
Their evaluation found varying levels of increases in HMSPI scores from 2005 to 2014 in every state, which could indicate that states are becoming better prepared to handle a medical surge. The scores also indicated that ideal readiness had not yet been achieved in any state before the COVID-19 pandemic.
“This is just the starting point. We need to better understand the ability of our nation’s hospitals to save lives in times of crisis,” said Dr. Marcozzi. This information, and follow-up studies building from this work, will be key to better matching states’ healthcare resources to their population to assure optimal care is delivered. Dr. Marcozzi described one follow-up study that would be impactful would be to use data from the COVID-19 pandemic to see whether the index was predictive to indicate which hospitals were most prepared for the pandemic surge based on their patient outcomes.
“This pioneering work is a needed advancement that could allow for a transparent assessment of a hospital’s ability to save lives in a large-scale emergency,” Dr. Marcozzi said. “The COVID-19 pandemic demonstrated that there is still plenty of room for improvement in the ability of our nation’s healthcare system to triage and manage multiple patients in a crisis and that translates into lives lost, unnecessarily. Our research is dedicated to those who lost their lives in this tragedy and other mass casualty events. We can do better.”
National health leadership organizations, such as the U.S. Centers for Medicare and Medicaid Services, the Assistant Secretary for Preparedness and Response, the Joint Commission, and the American Medical Association, as well as state and local emergency planners, could all potentially benefit from the use of HMSPI scores, according to Dr. Marcozzi. The tool could be used to support data-driven policy development and resource allocation to close gaps and assure that individuals get the care they need, when then need it, during a crisis.
Ricardo Pietrobon, MD, PhD, MBA, Adjunct Associate Professor of Emergency Medicine at UMSOM, Nicole Baehr, Manager of Operations at UMMC, and Brian J. Browne, MD, Professor and Chair of the Department of Emergency Medicine, were co-authors on this study. Researchers from the University of Nebraska Medical Center, University of Miami, and the U.S. Department of Veterans Affairs also participated in this research. The study was funded by the Bipartisan Commission on Biodefense.
“The COVID-19 pandemic taught us that we need to be better prepared for the unexpected crisis,” said E. Albert Reece, MD, PhD, MBA, Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. “Having an important metric like the HMSPI could be a game changer that ultimately saves lives during a surge by helping hospitals identify and fix their vulnerabilities.

SharecloseShare pageCopy linkAbout sharingimage copyrightReutersCoronavirus cases in the UK have risen above 30,000 for first time since January, official figures show.Wednesday’s data showed there had been a further 32,548 confirmed Covid cases.And there were another 33 deaths reported within 28 days of a positive Covid test.It comes as Boris Johnson has defended the government’s approach to easing England’s lockdown, saying the link between infection and serious disease and death has been “severed”. The prime minister has pledged to scrap most of England’s coronavirus regulations at step four of the roadmap out of lockdown, expected on 19 July.It means the government is now braced for a surge in coronavirus cases, possibly around 100,000 a day, as restrictions are lifted.Millions could end up self-isolating this summerWhat are the self-isolation rules if I’m fully vaccinated?I’m fully vaccinated, but how can I prove it?How could life change on 19 July?Speaking at Prime Minister’s Questions, Mr Johnson said it was “certainly true” there was a “wave of cases because of the Delta variant” of the virus.”But scientists are also absolutely clear that we have severed the link between infection and serious disease and death,” he said.”Currently there are only a 30th of the deaths that we were seeing at an equivalent position in previous waves of this pandemic.”However, on Monday the government’s chief scientific adviser Sir Patrick Vallance was more cautious, saying vaccines had “weakened the link between cases and hospitalisations, but it’s a weakened link, not a completely broken link”.Wednesday’s daily figure for Covid cases in the UK is above 30,000 for the first time since 24 January.In terms of hospitalisations, England is seeing more than 330 admissions a day on average at the moment. The most recent day – Monday – saw 416 admitted.As of Wednesday, 2,144 people are in hospital in England with Covid – the first time this figure has topped 2,000 since April.Wednesday’s case total represents an increase from 28,700 on Tuesday. It is not unusual for there to be a big jump on a Wednesday as a result of a weekend effect – slightly less testing is done.What’s important is the trend. Week on week this represents a 43% rise. That is actually down on what has been seen recently. They are going up quickly, but not as quickly as last week.It’s too early to say whether that is part of a longer-term pattern. But what is certain is that government officials are watching this data like hawks.The policy of opening up in England is based on the hope that the virus will soon hit the wall of immunity built up by the vaccination programme and natural infection.Ministers have said we should be prepared to see 100,000 cases a day. But they are hoping this wave of infection peaks well before that.Because while the vaccination programme has weakened the link between cases and hospitalisation, it has not broken it entirely.On current trends that many infections would lead to 2,000 daily admissions – twice what the NHS would normally see in the depths of winter for all types of respiratory illness.The PM has also defended the timescale for ending self-isolation for contacts of Covid, insisting it is a “sensible approach”.The government has said people who are fully vaccinated will not have to self-isolate if they come into contact with someone who has tested positive for Covid-19 from 16 August.Giving evidence to the Commons Liaison Committee, Mr Johnson rejected the suggestion 16 August had been chosen because it was when the government expected the population to have reached herd immunity .”That’s not the consideration… it’s the time by which we feel that there will have been much more progress on vaccination,” he said.And the PM said to do it any sooner would “effectively be allowing many more people to be vector of disease.””All decisions are a balance of risk,” he said.Asked how many people the government expected to end up self-isolating over the next month, he said: “That will depend on the spread. I haven’t seen any data on that. It will depend on the numbers.”Meanwhile, World Health Organization emergencies director Dr Mike Ryan has urged countries to use extreme caution when reopening their economies from Covid restrictions so as “not to lose the gains you have made”.Asked at a briefing if the UK was aiming for herd immunity, Dr Ryan said: “I’m not aware that that’s the logic driving our colleagues in the United Kingdom, I suspect it’s not.He said the argument that it was better to infect more people was morally empty and epidemiologically stupid.Labour’s leader Sir Keir Starmer has warned the prime minister he is leading the country into a “summer of chaos and confusion” over plans to ease lockdown.At PMQs, he said the country should open up “in a controlled way” and urged Mr Johnson to ensure masks still have to be worn on public transport.Face masks will no longer be legally required and distancing rules will be scrapped at the final stage of England’s Covid lockdown roadmap. The lifting of rules on 19 July will be confirmed next Monday after a review of the latest data.WHICH ENGLAND STAR WOULD YOU WANT AS YOUR BROTHER?: Find out who Peter Crouch picksCOMPANIES ON THE FRONT LINE OF BREXIT: Navigating Britain’s new trading relationships

The highly contagious Delta variant of the coronavirus is now the dominant variant in the United States, according to new estimates from the Centers for Disease Control and Prevention. The agency calculates that Delta accounts for 51.7 percent of coronavirus infections.As expected by health officials, Delta, which was first identified in India, has rapidly overtaken Alpha, the variant that spread through the United States this spring. Alpha, first detected in Britain, now makes up just 28.7 percent of infections, according to the C.D.C. Still, overall, the average numbers of new virus cases and deaths across the country, as well as hospitalizations, are significantly down from the devastating peaks during previous national surges.Although Delta is highly contagious, research suggests that most vaccines still provide good protection against it — and remain highly effective at preventing hospitalizations and deaths. In England, for instance, where the variant now causes almost all infections, case numbers have risen sharply in recent weeks, but hospitalization rates have increased more slowly and remain low. Next week, a final decision will be made about whether to lift most remaining restrictions in England, including mask rules, on July 19.In the United States, 67.1 percent of adults have had at least one vaccine dose as of Tuesday, and 58.3 percent are fully vaccinated. Studies suggest that a single shot of a two-dose regimen provides only weak protection against Delta, and public health experts have been encouraging Americans to get fully vaccinated as soon as possible.Vaccination coverage remains highly uneven, however, both in the United States and globally, and public health experts say Delta poses a serious threat to unvaccinated populations. On Tuesday, President Biden again urged Americans to get their shots, citing concerns about Delta.“It works. It’s free. And it’s never been easier, and it’s never been more important,” he said. “Do it now — for yourself and the people you care about, for your neighborhood, for your country. It sounds corny, but it’s a patriotic thing to do.”Health experts say the Biden administration may need to take more aggressive action to encourage vaccination, including urging employers and schools to adopt vaccine mandates. As of Tuesday, providers were administering about 0.87 million doses per day on average, about a 74 percent decrease from the peak of 3.38 million reported on April 13, according to federal data.As for the virus itself, the country has been averaging fewer than 15,000 new cases a day for nearly a month, the lowest levels since testing became widely available and a fraction of what was reported in January, when the nation routinely identified more than 200,000 cases in a day. In recent days, however, the average number of new cases nationally has started to trend slightly upward, driven largely by localized outbreaks in places with low vaccination rates, including parts of Missouri, Arkansas and Nevada.As the Delta variant spreads across the globe, the World Health Organization recently reiterated longstanding guidance that everyone, vaccinated or not, wear masks as a precaution, but the C.D.C. has not changed its advice that those who are fully vaccinated can skip masks in most situations. U.S. health officials have suggested that the W.H.O.’s blanket suggestion was informed by its global purview, since many countries have had far less access to vaccines than the United States.At a news conference on Tuesday, Jen Psaki, the White House press secretary, said that the Biden administration was unlikely to impose new national mitigation measures, even if cases rise.“The states are going to have to make evaluations and local communities are going to have to make evaluations about what’s in their interests,” she said.Mitch Smith contributed reporting.

“Droplet-array sandwiching” is a liquid-handling technique in which tiny droplet pairs laid out on opposite surfaces are mixed by bringing the surfaces together. However, this approach is limited to batch operations involving all droplets. Recently, scientists from Ritsumeikan University, Japan, found a way to electrically control the height of individual droplets, allowing them to select which droplet pairs should merge. Their method could replace manual tools such as pipettes and speed up drug screening.
Miniaturization is rapidly reshaping the field of biochemistry, with emerging technologies such as microfluidics and “lab-on-a-chip” devices taking the world by storm. Chemical reactions that were normally conducted in flasks and tubes can now be carried out within tiny water droplets not larger than a few millionths of a liter. Particularly, in droplet-array sandwiching techniques, such tiny droplets are orderly laid out on two parallel flat surfaces opposite to each other. By bringing the top surface close enough to the bottom one, each top droplet makes contact with the opposite bottom droplet, exchanging chemicals and transferring particles or even cells. In quite a literal way, these droplets can act as small reaction chambers or cell cultures, and they can also fulfill the role of liquid-handling tools such as pipettes but on a much smaller scale.
The problem with droplet-array sandwiching is that there is no individual control of droplets; once the top surface is lowered, each droplet on the bottom surface necessarily makes contact with one on the top surface. In other words, this technology is limited to batch operations, which limits its versatility and makes it costlier. Could there be a simple way to select which droplets should make contact when the surfaces are brought closer together?
Thanks to Professor Satoshi Konishi and his colleagues at Ritsumeikan University, Japan, the answer is a resounding yes! In a recent study published in Scientific Reports, this team of scientists presented a novel technique that allows one to individually select droplets for contact in droplet-array sandwiching. The idea behind their approach is rather straightforward: if we could control the height of individual droplets on the bottom surface to make some stand taller than others, we could bring both surfaces close together such that only those droplets make contact with their counterparts while sparing the rest. How this was actually achieved, however, was a bit trickier.
The researchers had previously attempted to use electricity to control the “wettability” of the dielectric material in the area below each droplet. This approach, known as “electrowetting-on-dielectric (EWOD),” lets one slightly alter the balance of forces that holds a water droplet together when resting on a surface. By applying an electric voltage under the droplet, it is possible to make it spread out slightly, increasing its area and reducing its height. However, the team found that this process was not easily reversible, as droplets would not spontaneously recover their original height once the voltage was turned off.
To tackle this problem, they developed an EWOD electrode with a hydrophilic-hydrophobic pattern. When the electrode is turned on, the previously described process makes the droplet on top of it spread out and become shorter. Conversely, when the electrode is turned off, the outer hydrophobic part of the electrode repels the droplet while the inner hydrophilic part attracts it. This restores the original shape, and height, of the droplet!
The researchers showcased their method by laying out multiple EWOD electrodes on the bottom surface of a droplet-array sandwiching platform. By simply applying voltage to selected electrodes, they could easily choose which pairs of droplets came into contact when the top platform was lowered. In their demonstration, they transferred red dye from the top droplets to only some of the bottom droplets. “Our approach can be used to electrically set up individual contacts between droplets, allowing us to effortlessly control the concentration of chemicals in these droplets or even transfer living cells from one to another,” explains Prof. Konishi.
This study paves the way for the potentially fruitful combination of droplet-handling techniques and automation. “We envision that lab-on-chip technology using droplets will replace conventional manual operations using tools such as pipettes, thereby improving the efficiency of drug screening. In turn, this will accelerate the process of drug discovery,” highlights Prof. Konishi. He adds that culturing cells in hanging droplets, which has been used in the field of cell biology, will also make cell-based evaluation of drugs and chemicals cheaper and faster, representing a valuable tool for biochemistry and cell biology.
Let us hope the fruits of this technology “drop” just around the corner!
Story Source:
Materials provided by Ritsumeikan University. Note: Content may be edited for style and length.

Children who eat slower are less likely to be extroverted and impulsive, according to a new study co-led by the University at Buffalo and Children’s Hospital of Philadelphia.
The research, which sought to uncover the relationship between temperament and eating behaviors in early childhood, also found that kids who were highly responsive to external food cues (the urge to eat when food is seen, smelled or tasted) were more likely to experience frustration and discomfort and have difficulties self-soothing.
These findings are critical because faster eating and greater responsiveness to food cues have been linked to obesity risk in children, says Myles Faith, PhD, co-author and professor of counseling, school and educational psychology in the UB Graduate School of Education.
The research, published in June in Pediatric Obesity, supports the integration of temperament into studies of and treatment for childhood obesity, a connection Faith deemed in need of further exploration in a previous study he co-led.
“Temperament is linked to many child developmental and behavioral outcomes, yet despite emerging evidence, few studies have examined its relationship with pediatric obesity,” said co-lead investigator Robert Berkowitz, MD, emeritus professor at the University of Pennsylvania and director of the Weight and Eating Disorders Research Program at Children’s Hospital of Philadelphia.
Co-lead investigator Alyssa Button, doctoral candidate in the UB Graduate School of Education, is the first author.
The researchers surveyed 28 participants beginning a family intervention program to reduce eating speed among 4- to 8-year-old children with or at risk for obesity.
The study examined the associations between three eating behaviors and three facets of temperament. The eating behaviors included responsiveness to feeling full (internal food cues); responsiveness to seeing, smelling and tasting food (external food cues); and eating speed. Temperament consisted of extroversion and impulsivity (also known as surgency); self-control; and the inability to self-sooth negative emotions such as anger, fear and sadness.
Among the findings is that children who respond well to feeling full exhibit more self-control. More research is needed to understand the role parents play in their children’s temperament and eating behavior, says Button.
“Parents may use food to soothe temperamental children and ease negative emotions,” says Button, also a senior research support specialist in the Department of Pediatrics in the Jacobs School of Medicine and Biomedical Sciences at UB. “Future research should examine the different ways parents feed their children in response to their temperament, as well as explore whether the relationship between temperament and eating behaviors is a two-way street. Could the habit of eating slower, over time, lead to lower impulsiveness?”
“This study established relationships between temperament and eating patterns in children; however, there is still the question of chicken-and-egg and which comes first?” says Faith. “Research that follows families over time is needed to untangle these developmental pathways.”
The study was funded by the Children’s Hospital of Philadelphia.
Story Source:
Materials provided by University at Buffalo. Original written by Marcene Robinson. Note: Content may be edited for style and length.

Immunologists at St. Jude Children’s Research Hospital have identified a biological pathway that selectively controls how key immune cells, called T follicular helper cells, mature into functional components of the immune system.
The finding offers the promise of developing drugs to activate the metabolic pathway to enhance the effectiveness of vaccines, including those that protect against COVID-19. Such medications could stimulate the immune system to respond more vigorously following immunization to produce more antibodies against a virus or bacterium.
The work also lays the foundation for drugs that dial down the pathway to alleviate autoimmune diseases such as lupus. In such disorders, an overactive immune system produces antibodies that attack the body’s own tissues.
Led by Hongbo Chi, Ph.D. of the Department of Immunology, the researchers published their findings today in Nature.
Regulating the adaptive immune response
Chi and colleagues identified a metabolic control pathway that selectively regulates the development of specialized immune cells in the adaptive immune system. These cells are called T follicular helper cells.

Microscopists have long sought to find a way to produce high-quality, deep-tissue imaging of living subjects in a timely fashion. Until now, they had to choose between image quality or speed when it comes to looking into the inner workings of complex biological systems.
Such a development would have a powerful impact on researchers in biology and in neuroscience, experts say. Now Dushan N. Wadduwage, a John Harvard Distinguished Science Fellow in Imaging at the FAS Center of Advanced Imaging, along with a team from MIT, detailed a new technique that would make that possible in a report in Science Advances.
In the paper, the team presents a new process that uses computational imaging to get high resolution images at a rate 100 to 1,000 times faster than other state-of-the-art technologies that use complex algorithms and machine learning. The method can turn a process that takes months into a matter of days.
The system, called De-scattering with Excitation Patterning (or DEEP), is believed to be the first of its kind and may one day lead to new understandings of how complicated tissue specimens, like the brain, functions because it can take images that aren’t possible with other microscopes.
“Because this has the potential to actually speed up [what you can take an image of along with how fast you can do it], scientists will be able to image fast processes they haven’t been able to capture before, like what happens when a neuron fires or how the signals move around in the brain,” Wadduwage said. “Also, because it’s technically faster, you can image a larger volume of area at one time, not just a small field of view as you would with a slower imaging system. It’s like being able to look at a much larger picture, and this is very important for neuroscientists and other biologists to actually get better statistics as well as to see what’s happening around the area being imaged.”
The system works like many other animal imaging techniques. Near-infrared laser light is used to penetrate deep through biological tissue that scatters the light. That light excites the fluorescent molecules the researchers want to image and emit signals that the microscope captures to form an image.
There have been two main ways these types of images are taken. Point-scanning multiphoton microscopy can penetrate deep into a specimen and capture high quality images. The drawback is the process is extremely slow because the image is formed one point at a time. If the researcher is looking to capture a centimeter-sized image, for example, it can take months. It also limits studies of fast biological dynamics, such as neurons firing. The other method is call temporal focusing microscopy, which is much faster and can capture images at a wider scale but is unable to capture high resolution images at anything deeper than few millionths of a meter. The fluorescent light scatters too much, causing the image to degrade when the camera detects it.
DEEP, however, allows for fast tissue penetration at a wide scale and produces high-resolution images. The system projects a wide light into the subject as in the temporal microscopy method, but that laser light is in a specific pattern. The computational imaging algorithm knowing the initial pattern takes in the information gathered to reverse the process when it gets scattered and then reconstructs it, descattering the image. This is especially notable since it takes the reconstruction of structural features from millions of measurements to tens and hundreds. DEEP can image hundreds of microns deep through scattering tissue comparable to point-scanning techniques.
DEEP is still early years of development but is emerging from its proof-of-concept phase.
“We showed that we can image about 300 microns into the brains of live mice,” Wadduwag said. “But since this is only the first demonstration, almost all aspects of the technique have room for improvement.”
Story Source:
Materials provided by Harvard University. Original written by Juan Siliezar. Note: Content may be edited for style and length.