Wireless system suggests future where doctors could implant sensors to track tumors or even dispense drugs

Date:
August 20, 2018

Source:
Massachusetts Institute of Technology, CSAIL

Summary:
Scientists have developed a system that can pinpoint the location of ingestible implants inside the body using low-power wireless signals.

 
Medical processes like imaging often require cutting someone open or making them swallow huge tubes with cameras on them. But what if could get the same results with methods that are less expensive, invasive and time-consuming?

Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) led by professor Dina Katabi are working on exactly that with ReMix, a system that they describe as an “in-body GPS.” ReMix can pinpoint the location of ingestible implants inside the body using low-power wireless signals. In animal tests the team demonstrated that they can track implants with centimeter-level accuracy, and said that one day similar implants could be used to deliver drugs to specific regions in the body.

To test ReMix, Katabi’s group first implanted a small marker in animal tissues. To track its movement, they used a wireless device that reflects radio signals at the patient, and a special algorithm to pinpoint the exact location of the marker. The team used a wireless technology that they’ve previously demonstrated to detect heart rate, breathing and movement.

Interestingly, the marker inside the body does not need to transmit any wireless signal. It simply reflects the signal transmitted by a device outside the body, without needing a battery or any other external source of energy.

A key challenge in using wireless signals in this way is the many competing reflections that bounce off a person’s body. In fact, the signals that reflect off a person’s skin are actually 100 million times more powerful than the signals of the metal marker itself.

To overcome this, the team designed an approach that essentially separates the interfering skin signals from the ones they’re trying to measure. They did this using a small semiconductor device called a “diode” that can mix signals together so that the team can then filter out the skin-related signals. For example, if the skin reflects at frequencies of F1 and F2, the diode creates new combinations of those frequencies such as F1-F2 and F1+F2. When all of the signals reflect back to the system, the system only picks up the combined frequencies , thereby filtering out the original frequencies that came from the patient’s skin.

“The ability to continuously sense inside the human body has largely been a distant dream,” says Romit Roy Choudhury, a professor of electrical engineering and computer science at the University of Illinois, who was not involved in the research. “One of the roadblocks has been wireless communication to a device and its continuous localization. ReMix makes a leap in this direction by showing that the wireless component of implantable devices may no longer be the bottleneck.”

One potential application for ReMix is in proton therapy, a type of cancer treatment that involves bombarding tumors with beams of magnet-controlled protons. The approach allows doctors to prescribe higher doses of radiation, but requires a very high degree of precision, which means that it’s usually limited to only certain cancers.

Its success hinges on something that’s actually quite unreliable: a tumor staying exactly where it is during the radiation process. If a tumor moves, then healthy areas could be exposed to the radiation. But with a small marker like ReMix’s, doctors could better determine the location of a tumor in real-time, and be able to either pause the treatment or steer the beam into the right position to deal with the movement. (To be clear, ReMix is not yet accurate enough to be used in clinical settings — Katabi says a margin of error closer to a couple of millimeters would be necessary for actual implementation.)

Looking ahead

There are still many challenges ahead for improving ReMix. The team next hopes to combine the wireless data with medical information like MRI scans to further improve the system’s accuracy. In addition, the team will continue to reassess the algorithm and the various trade-offs needed to account for the complexity of different peoples’ bodies.

“We want a model that’s technically feasible, while still complex enough to accurately represent the human body,” says PhD student Deepak Vasisht, lead author on the new paper. “If we want to use this technology on actual cancer patients one day, it will have to come from better modeling a person’s physical structure.”

ReMix was developed in collaboration with researchers from Massachusetts General Hospital (MGH). The team says that such systems could help enable more widespread adoption of proton therapy centers, of which there are only about 100 globally.

“One reason that [proton therapy] is so expensive is because of the cost of installing the hardware,” says Vasisht. “If these systems can encourage more applications of the technology, there will be more demand, which will mean more therapy centers, and lower prices for patients.”

Story Source:

Materials provided by Massachusetts Institute of Technology, CSAILNote: Content may be edited for style and length.

 

Source: Massachusetts Institute of Technology, CSAIL. “A GPS for inside your body: Wireless system suggests future where doctors could implant sensors to track tumors or even dispense drugs.” ScienceDaily. ScienceDaily, 20 August 2018. <www.sciencedaily.com/releases/2018/08/180820085158.htm>.

Date:
August 20, 2018

Source:
American Geophysical Union

Summary:
Thin ribbons of purple and white light that sometimes appear in the night sky were dubbed a new type of aurora when brought to scientists’ attention in 2016. But new research suggests these mysterious streams of light are not an aurora at all but an entirely new celestial phenomenon.

 

The atmospheric phenomenon ‘STEVE’ which appears as a purple and green light ribbon in the sky.
Credit: © Ryan / Fotolia

 

 

Thin ribbons of purple and white light that sometimes appear in the night sky were dubbed a new type of aurora when brought to scientists’ attention in 2016. But new research suggests these mysterious streams of light are not an aurora at all but an entirely new celestial phenomenon.

Amateur photographers had captured the new phenomenon, called STEVE, on film for decades. But the scientific community only got wind of STEVE in 2016. When scientists first looked at images of STEVE, they realized the lights were slightly different than light from typical auroras but were not sure what underlying mechanism was causing them.

In a new study, researchers analyzed a STEVE event in March 2008 to see whether it was produced in a similar manner as the aurora, which happens when showers of charged rain down into Earth’s upper atmosphere. The study’s results suggest STEVE is produced by a different atmospheric process than the aurora, making it an entirely new type of optical phenomenon.

“Our main conclusion is that STEVE is not an aurora,” said Bea Gallardo-Lacourt, a space physicist at the University of Calgary in Canada and lead author of the new study in Geophysical Research Letters, a journal of the American Geophysical Union. “So right now, we know very little about it. And that’s the cool thing, because this has been known by photographers for decades. But for the scientists, it’s completely unknown.”

The study authors have dubbed STEVE a kind of “skyglow,” or glowing light in the night sky, that is distinct from the aurora.

Studying STEVE can help scientists better understand the upper atmosphere and the processes generating light in the sky, according to the authors.

“This is really interesting because we haven’t figured it out and when you get a new problem, it’s always exciting,” said Joe Borovsky, a space physicist at the Space Science Institute in Los Alamos, New Mexico who was not connected to the new study. “It’s like you think you know everything and it turns out you don’t.”

A different kind of light show

Auroras are produced when electrons and protons from Earth’s magnetosphere, the region around Earth dominated by its magnetic field, rain down into the ionosphere, a region of charged particles in the upper atmosphere. When these electrons and protons become excited, they emit light of varying colors, most often green, red and blue.

A group of amateur auroral photographers brought STEVE to scientists’ attention in 2016. A Facebook ground called the Alberta Aurora Chasers had occasionally noticed bright, thin streams of white and purple light running east to west in the Canadian night sky when they photographed the aurora.

Auroras are visible every night if viewing conditions are right, but the thin light ribbons of STEVE were only visible a few times per year. The light from STEVE was also showing up closer to the equator than the aurora, which can only be seen at high latitudes.

The photographers first thought the light ribbons were created by excited protons, but protons can only be photographed with special equipment. The light protons produce falls out of the range of wavelengths picked up by normal cameras.

The aurora chasers dubbed the light ribbon occurrences “Steve,” a reference to the 2006 film Over the Hedge. When researchers presented data about the unusual lights at a 2016 scientific conference, a fellow space physicist proposed converting the name into the backronym STEVE, which stands for Strong Thermal Emission Velocity Enhancement, and the researchers adopted it.

Where does STEVE come from?

Scientists then started using data from satellites and images from ground-based observatories to try to understand what was causing the unusual light streaks. The first scientific study published on STEVE found a stream of fast-moving ions and super-hot electrons passing through the ionosphere right where STEVE was observed. The researchers suspected these particles were connected to STEVE somehow but were unsure whether they were responsible for producing it.

After that first study, of which Gallardo-Lacourt was a co-author, the researchers wanted to find out if STEVE’s light is produced by particles raining down into the ionosphere, as typically happens with the aurora, or by some other process. In the new study, Gallardo-Lacourt and her colleagues analyzed a STEVE event that happened over eastern Canada on March 28, 2008, using images from ground-based cameras that record auroras over North America.

They coupled the images with data from NOAA’s Polar Orbiting Environmental Satellite 17 (POES-17), which happened to pass directly over the ground-based cameras during the STEVE event. The satellite is equipped with an instrument that can measure charged particles precipitating into the ionosphere.

The study’s results suggest STEVE is an entirely new phenomenon distinct from typical auroras. The POES-17 satellite detected no charged particles raining down to the ionosphere during the STEVE event, which means it is likely produced by an entirely different mechanism, according to the authors.

The researchers said STEVE is a new kind of optical phenomenon they call “skyglow.” Their next step is to see whether the streams of fast ions and hot electrons in the ionosphere are creating STEVE’s light, or if the light is produced higher up in the atmosphere.

Story Source:

Materials provided by American Geophysical UnionNote: Content may be edited for style and length.


Journal Reference:

  1. B. Gallardo-Lacourt, J. Liang, Y. Nishimura and E. Donovan. On the Origin of STEVE: Particle Precipitation or Ionospheric Skyglow? Geophysical Research Letters, 2018 DOI: 10.1029/2018GL078509

 

Source: American Geophysical Union. “New kind of aurora is not an aurora at all.” ScienceDaily. ScienceDaily, 20 August 2018. <www.sciencedaily.com/releases/2018/08/180820104202.htm>.

Date:
August 20, 2018

Source:
NASA/Jet Propulsion Laboratory

Summary:
Using data from NASA’s Moon Mineralogy Mapper instrument, scientists have identified three specific signatures that definitively prove there is water ice at the surface of the Moon.

 

The image shows the distribution of surface ice at the Moon’s south pole (left) and north pole (right), detected by NASA’s Moon Mineralogy Mapper instrument. Blue represents the ice locations, plotted over an image of the lunar surface, where the gray scale corresponds to surface temperature (darker representing colder areas and lighter shades indicating warmer zones). The ice is concentrated at the darkest and coldest locations, in the shadows of craters. This is the first time scientists have directly observed definitive evidence of water ice on the Moon’s surface.
Credit: NASA

 

 

In the darkest and coldest parts of its polar regions, a team of scientists has directly observed definitive evidence of water ice on the Moon’s surface. These ice deposits are patchily distributed and could possibly be ancient. At the southern pole, most of the ice is concentrated at lunar craters, while the northern pole’s ice is more widely, but sparsely spread.

A team of scientists, led by Shuai Li of the University of Hawaii and Brown University and including Richard Elphic from NASA’s Ames Research Center in California’s Silicon Valley, used data from NASA’s Moon Mineralogy Mapper (M3) instrument to identify three specific signatures that definitively prove there is water ice at the surface of the Moon.

M3, aboard the Chandrayaan-1 spacecraft, launched in 2008 by the Indian Space Research Organization, was uniquely equipped to confirm the presence of solid ice on the Moon. It collected data that not only picked up the reflective properties we’d expect from ice, but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice.

Most of the newfound water ice lies in the shadows of craters near the poles, where the warmest temperatures never reach above minus 250 degrees Fahrenheit. Because of the very small tilt of the Moon’s rotation axis, sunlight never reaches these regions.

Previous observations indirectly found possible signs of surface ice at the lunar south pole, but these could have been explained by other phenomena, such as unusually reflective lunar soil.

With enough ice sitting at the surface — within the top few millimeters — water would possibly be accessible as a resource for future expeditions to explore and even stay on the Moon, and potentially easier to access than the water detected beneath the Moon’s surface.

Learning more about this ice, how it got there, and how it interacts with the larger lunar environment will be a key mission focus for NASA and commercial partners, as we endeavor to return to and explore our closest neighbor, the Moon.

The findings were published in the Proceedings of the National Academy of Sciences on August 20, 2018.

NASA’s Jet Propulsion Laboratory, Pasadena, California, designed and built the moon mineralogy mapper instrument and was home to its project manager.

Story Source:

Materials provided by NASA/Jet Propulsion LaboratoryNote: Content may be edited for style and length.


Journal Reference:

  1. Shuai Li, Paul G. Lucey, Ralph E. Milliken, Paul O. Hayne, Elizabeth Fisher, Jean-Pierre Williams, Dana M. Hurley, Richard C. Elphic. Direct evidence of surface exposed water ice in the lunar polar regionsProceedings of the National Academy of Sciences, 2018; 201802345 DOI: 10.1073/pnas.1802345115

 

Source: NASA/Jet Propulsion Laboratory. “Ice confirmed at the moon’s poles.” ScienceDaily. ScienceDaily, 20 August 2018. <www.sciencedaily.com/releases/2018/08/180820203638.htm>.

Urgent need to examine systemic causes of declining health in the US

Date:
August 15, 2018

Source:
BMJ

Summary:
The ongoing opioid epidemic in the United States is a key contributor to the most recent declines in life expectancy, suggests a new study.

 

Life expectancy is a measure of the health and wellbeing of a population. Widespread or sustained declines in life expectancy may signal problems in a nation’s social and economic conditions or in the provision or quality of its healthcare services.
Credit: © Stuart / Fotolia

 

 

The ongoing opioid epidemic in the United States is a key contributor to the most recent declines in life expectancy, suggests a study published by The BMJ today.

A second study shows an increase in US death rates in midlife (people aged between 25-64 years) involving all major racial groups, and cites a broad range of conditions as potential causes.

Together, these findings point to an urgent need to examine systemic causes of declining health in the US.

Life expectancy is a measure of the health and wellbeing of a population. Widespread or sustained declines in life expectancy may signal problems in a nation’s social and economic conditions or in the provision or quality of its healthcare services.

The first study, authored by Jessica Ho at the University of Southern California and Arun Hendi at Princeton University, looked at trends in life expectancy across 18 high income countries and found that most countries experienced declines in life expectancy in 2015.

This is the first time in recent decades that these many high income countries simultaneously experienced declines in life expectancy for both men and women, and the size of these declines were larger than in the past.

In the non-US countries, these declines were largely concentrated at ages 65 and older and likely related to a particularly severe influenza season. The main causes of death driving these declines included influenza and pneumonia, respiratory disease, cardiovascular disease, and Alzheimer’s disease and other mental and nervous system disorders.

But in the US, the decline was concentrated at younger ages, particularly those in their 20s and 30s, and largely driven by increases in drug overdose deaths related to its ongoing opioid epidemic. The authors point out that the US decline is particularly troubling in light of its already low life expectancy ranking relative to its peer countries.

And unlike other countries in the study, life expectancy in both the US and the UK continued to decline in 2016, which the researchers say raises questions about future trends in these countries.

A second study, also published today, suggests that the problem is larger than the opioid epidemic. It shows increased death rates from dozens of causes among people in all racial and ethnic groups.

Using national data to compare midlife death patterns from 1999 to 2016, Steven Woolf at Virginia Commonwealth University and colleagues found that although drug overdoses, suicides, and alcoholism were the leading cause of excess deaths, mortality rates also increased dramatically for organ diseases involving the heart, lung, and other body systems. “The opioid epidemic is the tip of an iceberg,” said Woolf.

Previous studies had documented a rise in “deaths of despair” among middle-aged white people in the US, but this is the first study to show that the trend now encompasses multiple body systems and is striking multiple racial and ethnic groups. These increases are offsetting years of progress in lowering death rates among black and Hispanic adults.

Furthermore, although overall death rates were higher among men than among women, the relative increase in fatal drug overdoses and suicides was greater in women, consistent with other reports of the worsening health disadvantage among women in the US.

The authors say “no single factor, such as opioids, explains this phenomenon” and suggest that their study “signals a systemic cause and warrants prompt action by policy makers to tackle the factors responsible for declining health in the US.”

Both studies are observational, so no firm conclusions can be drawn about cause and effect, and the authors highlight several limitations that may have affected their results.

Nevertheless, taken together, these two studies highlight warning signs that must not be ignored and should prompt urgent review of systemic causes of declining health in the US.

In a linked editorial, Domantas Jasilionis at the Max Planck Institute for Demographic Research in Germany says life expectancy is a key characteristic of human development and declines should be taken seriously. Historical evidence suggests that discontinuities in secular trends can lead to prolonged health crises — they are warning signs of fundamental and longstanding societal and health problems.

He points to the negative health consequences of growing social deprivation and austerity policies, but notes that high life expectancies in the UK and many other high income countries (including the Nordic countries with strong pro-equitable social policies) coexist with large or even increasing health disparities. In future, persisting notable health disadvantages of some population groups may become an important obstacle for sustainable health progress at the national level.*

He calls for more reliable data to underpin effective policies, and says “more effort must be made to convince international and national agencies to invest in robust register based systems that allow timely and accurate monitoring of changes in longevity,” he concludes.

Story Source:

Materials provided by BMJNote: Content may be edited for style and length.


Journal Reference:

  1. Jessica Y Ho, Arun S Hendi. Recent trends in life expectancy across high income countries: retrospective observational studyBMJ, 2018; k2562 DOI: 10.1136/bmj.k2562

 

Source: BMJ. “Widespread declines in life expectancy across high income countries coincide with rising young adult and midlife mortality in the United States: Urgent need to examine systemic causes of declining health in the US.” ScienceDaily. ScienceDaily, 15 August 2018. <www.sciencedaily.com/releases/2018/08/180815190526.htm>.

Date:
August 14, 2018

Source:
The Francis Crick Institute

Summary:
Chemicals produced by vegetables such as kale, cabbage and broccoli could help to maintain a healthy gut and prevent colon cancer, a new study shows.

 

This is a mouse colon from Cyp1a reporter mice after feeding with I3C.
Credit: Chris Schiering, Francis Crick Institute

 

 

Chemicals produced by vegetables such as kale, cabbage and broccoli could help to maintain a healthy gut and prevent colon cancer, a new study from the Francis Crick Institute shows.

 

The research, published in Immunity, shows that mice fed on a diet rich in indole-3-carbinol — which is produced when we digest vegetables from the Brassica genus — were protected from gut inflammation and colon cancer.

While the health benefits of vegetables are well-established, many of the mechanisms behind them remain unknown. This study offers the first concrete evidence of how I3C in the diet can prevent colon inflammation and cancer, by activating a protein called the aryl hydrocarbon receptor (AhR).

Gut reactions

AhR acts as an environmental sensor, passing signals to immune cells and epithelial cells in the gut lining to protect us from inflammatory responses to the trillions of bacteria that live in the gut.

“We studied genetically modified mice that cannot produce or activate AhR in their guts, and found that they readily developed gut inflammation which progressed to colon cancer,” explains first author Dr Amina Metidji from the Francis Crick Institute. “However, when we fed them a diet enriched with I3C, they did not develop inflammation or cancer. Interestingly, when mice whose cancer was already developing were switched to the I3C-enriched diet, they ended up with significantly fewer tumours which were also more benign.”

By studying both mice and mouse gut organoids — ‘mini guts’ made from stem cells — the researchers found that AhR is vital for repairing damaged epithelial cells. Without AhR, intestinal stem cells fail to differentiate into specialised epithelial cells that absorb nutrients or generate protective mucus. Instead, they divide uncontrollably which can ultimately lead to colon cancer.

Preventing colon cancer

“Seeing the profound effect of diet on gut inflammation and colon cancer was very striking,” says senior author Dr Gitta Stockinger, Group Leader at the Francis Crick Institute. “We often think of colon cancer as a disease promoted by a Western diet rich in fat and poor in vegetable content, and our results suggest a mechanism behind this observation. Many vegetables produce chemicals that keep AhR stimulated in the gut. We found that AhR-promoting chemicals in the diet can correct defects caused by insufficient AhR stimulation. This can restore epithelial cell differentiation, offering resistance to intestinal infections and preventing colon cancer.

“These findings are a cause for optimism; while we can’t change the genetic factors that increase our risk of cancer, we can probably mitigate these risks by adopting an appropriate diet with plenty of vegetables.”

As well as correcting altered AhR dependent gene expression, dietary I3C also had a surprising effect on unmodified mice with normal AhR expression. While normal mice fed on standard or I3C-enriched food did not develop tumours during the study, those fed on a ‘purified control diet’ did.

An ‘optimal’ diet?

Laboratory mice are usually fed a standard grain-based ‘chow’ which contains a mix of ingredients and nutrients. For dietary studies, they are given a ‘purified control diet’ so that researchers know exactly what is in the food. These are designed to precisely fulfil the animal’s nutritional needs while being free of allergens, pathogens or variable ingredients found in standard chow.

Purified control diets contain exact mixtures of carbohydrates, proteins, fats and fibres enriched with vitamins and minerals. However, the latest study suggests that these diets have fewer AhR-promoting chemicals than the standard chow or the I3C-enriched diet.

“Normal mice on the purified control diet developed colon tumours within 10 weeks, whereas mice on the standard chow didn’t develop any,” explains co-corresponding author Dr Chris Schiering, who worked on the study at the Crick and now works at Imperial College London. “This suggests that even without genetic risk factors, a diet devoid of vegetable matter can lead to colon cancer.”

From mouse to man

To follow up on their surprising findings, the team are now hoping to do further experiments in organoids made from human gut biopsies and eventually human trials.

“A number of epidemiological studies suggested that vegetables may be protective against cancer,” explains Gitta. “However, there is very little literature on which vegetables are the most beneficial or why. Now that we’ve demonstrated the mechanistic basis for this in mice, we’re going to investigate these effects in human cells and people. In the meantime, there’s certainly no harm in eating more vegetables!”

Professor Tim Key, Cancer Research UK’s expert on diet and cancer, said: “This study in mice suggests that it’s not just the fibre contained in vegetables like broccoli and cabbage that help reduce the risk of bowel cancer, but also molecules found in these vegetables too. This adds to the evidence that a healthy diet, rich in vegetables, is important. Further studies will help find out whether the molecules in these vegetables have the same effect in people, but in the meantime there are already plenty of good reasons to eat more vegetables”

Story Source:

Materials provided by The Francis Crick InstituteNote: Content may be edited for style and length.


Journal Reference:

  1. Amina Metidji, Sara Omenetti, Stefania Crotta, Ying Li, Emma Nye, Ellie Ross, Vivian Li, Muralidhara R. Maradana, Chris Schiering, Brigitta Stockinger. The Environmental Sensor AHR Protects from Inflammatory Damage by Maintaining Intestinal Stem Cell Homeostasis and Barrier IntegrityImmunity, 2018; DOI: 10.1016/j.immuni.2018.07.010

 

Source: The Francis Crick Institute. “Chemicals found in vegetables prevent colon cancer in mice.” ScienceDaily. ScienceDaily, 14 August 2018. <www.sciencedaily.com/releases/2018/08/180814173648.htm>.

Date:
August 13, 2018

Source:
Broad Institute of MIT and Harvard

Summary:
A research team reports a new kind of genome analysis that could identify large fractions of the population who have a much higher risk of developing serious common diseases, including coronary artery disease, breast cancer, or type 2 diabetes. These tests, which use information from millions of places in the genome to ascertain risk for five diseases, can flag greater likelihood of developing the potentially fatal conditions well before any symptoms appear.

 

The researchers gathered data from large-scale genome-wide association studies to identify genetic variants associated with each disease, and combined information from all of the variants into a single “polygenic risk test.”
Credit: Lauren Solomon

 

 

A research team at the Broad Institute of MIT and Harvard, Massachusetts General Hospital (MGH), and Harvard Medical School reports a new kind of genome analysis that could identify large fractions of the population who have a much higher risk of developing serious common diseases, including coronary artery disease, breast cancer, or type 2 diabetes.

 

These tests, which use information from millions of places in the genome to ascertain risk for five diseases, can flag greater likelihood of developing the potentially fatal conditions well before any symptoms appear. While the study was conducted with data from the UK, it suggests that up to 25 million people in the US may be at more than triple the normal risk for coronary artery disease, and millions more may be at similar elevated risk for the other conditions, based on genetic variation alone. The genomic information could allow physicians to focus particular attention on these individuals, perhaps enabling early interventions to prevent disease.

The research raises important questions about how this method, called polygenic risk scoring, should be further developed and used in the medical system. In addition, the authors note that the genetic tests are largely based on information from individuals of European descent, and the results underscore the need for larger studies of other ethnic groups to ensure equity. The study appears in Nature Genetics.

“We’ve known for long time that there are people out there at high risk for disease based just on their overall genetic variation,” said senior author Sekar Kathiresan, an institute member and director of the Cardiovascular Disease Initiative at the Broad Institute, as well as director of the Center for Genomic Medicine at MGH and a professor of medicine at Harvard Medical School. “Now, we’re able to measure that risk using genomic data in a meaningful way. From a public health perspective, we need to identify these higher-risk segments of the population so we can provide appropriate care.”

Kathiresan led the work with first authors Amit V. Khera, a cardiologist at MGH and junior faculty member in Kathiresan’s lab, and Mark Chaffin, a computational biologist also in Kathiresan’s lab.

To develop the algorithms for scoring disease risk, the researchers first gathered data from large-scale genome-wide association studies to identify genetic variants associated with coronary artery disease, atrial fibrillation, type 2 diabetes, inflammatory bowel disease, or breast cancer. For each disease, they applied a computational algorithm to combine information from all of the variants — most of which individually have an extremely small impact on risk — into a single number, or polygenic risk score. This number could be used to predict a person’s chances of getting these diseases based on his or her genome.

The team tested and validated the polygenic risk score algorithms on data from over 400,000 individuals in the UK Biobank, an extensive database of genomic data and medical information from participants of British ancestry.

Importantly, according to Khera, the people with high polygenic risk scores for coronary artery disease did not necessarily exhibit other warning signs of disease risk (such as hypertension or high cholesterol).

“These individuals, who are at several times the normal risk for having a heart attack just because of the additive effects of many variations, are mostly flying under the radar,” he explained. “If they came into my clinical practice, I wouldn’t be able to pick them out as high risk with our standard metrics. There’s a real need to identify these cases so we can target screening and treatments more effectively, and this approach gives us a potential way forward.”

Here’s how the score worked for coronary artery disease: The algorithm pored over more than 6.6 million locations in the genome to estimate a person’s risk of developing the deadly disease, which is the most common type of heart disease and a leading cause of death for adults in the United States. Of the individuals in the UK Biobank dataset, 8 percent were more than three times as likely to develop the disease compared to everyone else, based on their genetic variation. In absolute terms, only 0.8 percent of individuals with the very lowest polygenic risk scores had coronary artery disease, as compared to 11 percent for the people with the top scores.

For breast cancer, a leading cause of malignancy-related death in women, the polygenic predictor found that 1.5 percent of the UK Biobank population had more than triple the risk for having the disease when compared to everyone else. Those with the very highest polygenic risk scores had five times the risk — meaning, in absolute terms, that 19 percent of people with the top scores had breast cancer, versus about 4 percent of the remaining individuals. The researchers applied a similar approach to polygenic risk scoring for type 2 diabetes, atrial fibrillation, and inflammatory bowel disease.

To develop polygenic risk scoring tests for other common diseases, the team notes that additional research will be necessary to collect genome-wide association data and validate the scores with reference biobanks. In addition, the current polygenic risk calculations are largely derived from genetic studies done in people of European ancestry — so more studies are needed to optimize the algorithms for other ethnic groups.

Nevertheless, the researchers propose that it is time for the biomedical community to consider including this approach in clinical care. To do this, a number of factors need to be considered, such as: whether the disease has a genetic component; if the disease is prevalent enough in the general population to make screening worth incorporating into routine clinical care; and if knowing the genetic risk for a disease would be useful in guiding care to offset this inherited risk.

“Ultimately, this is a new type of genetic risk factor,” said Kathiresan. “We envision polygenic risk scores as a way to identify people at high or low risk for a disease, perhaps as early as birth, and then use that information to target interventions — either lifestyle modifications or treatments — to prevent disease. For heart attack, I foresee that each patient will have the opportunity to know his or her polygenic risk number in the near future, similar to way they can know their cholesterol number right now.”

Story Source:

Materials provided by Broad Institute of MIT and Harvard. Original written by Karen Zusi. Note: Content may be edited for style and length.


Journal Reference:

  1. Amit V. Khera, Mark Chaffin, Krishna G. Aragam, Mary E. Haas, Carolina Roselli, Seung Hoan Choi, Pradeep Natarajan, Eric S. Lander, Steven A. Lubitz, Patrick T. Ellinor, Sekar Kathiresan. Genome-wide polygenic scores for common diseases identify individuals with risk equivalent to monogenic mutationsNature Genetics, 2018; DOI: 10.1038/s41588-018-0183-z

 

Source: Broad Institute of MIT and Harvard. “Researchers predict risk for common deadly diseases from millions of genetic variants.” ScienceDaily. ScienceDaily, 13 August 2018. <www.sciencedaily.com/releases/2018/08/180813113309.htm>.

Date:
August 13, 2018

Source:
New York University

Summary:
A team of scientists has uncovered new molecular properties of water — a discovery of a phenomenon that had previously gone unnoticed.

 

Scuba diver looking at ice hole, while ice diving.
Credit: © kondratuk / Fotolia

 

 

A team of scientists has uncovered new molecular properties of water — a discovery of a phenomenon that had previously gone unnoticed.

Liquid water is known to be an excellent transporter of its own autoionization products; that is, the charged species obtained when a water molecule (H2O) is split into protons (H+) and hydroxide ions (OH?). This remarkable property of water makes it a critical component in emerging electrochemical energy production and storage technologies such as fuel cells; indeed, life itself would not be possible if water did not possess this characteristic.

Water is known to consist an intricate network of weak, directional interactions known as hydrogen bonds. For nearly a century, it was thought that the mechanisms by which water transports the H+ and OH? ions were mirror images of each other — identical in all ways except for directions of the hydrogen bonds involved in the process.

Current state-of-the-art theoretical models and computer simulations, however, predicted a fundamental asymmetry in these mechanisms. If correct, this asymmetry is something that could be exploited in different applications by tailoring a system to favor one ion over the other.

Experimental proof of the theoretical prediction has remained elusive because of the difficulty in directly observing the two ionic species. Different experiments have only provided glimpses of the predicted asymmetry.

A team of scientists at New York University, led by Professor Alexej Jerschow and including Emilia Silletta, an NYU postdoctoral fellow, and Mark Tuckerman, a professor of chemistry and mathematics at NYU, devised a novel experiment for nailing down this asymmetry. The experimental approach involved cooling water down to its so-called temperature of maximum density, where the asymmetry is expected to be most strongly manifest, thereby allowing it to be carefully detected.

It is common knowledge that ice floats on water and that lakes freeze from the top. This is because water molecules pack into a structure with lower density than that of liquid water — a manifestation of the unusual properties of water: the density of liquid water increases just above the freezing point and reaches a maximum at four degrees Celsius (39 degrees Fahrenheit), the so-called temperature of maximum density; this difference in density dictates that liquid is always situated below ice.

By cooling water down to this temperature, the team employed nuclear magnetic resonance methods (the same type of approach is medically in magnetic resonance imaging) to show that the difference in lifetimes of the two ions reaches a maximum value (the greater the lifetime, the slower the transport). By accentuating the difference in lifetimes, the asymmetry became glaringly clear.

As noted previously, water consists of one oxygen atom and two hydrogen atoms, but the hydrogen atoms are relatively mobile and can hop from one molecule to another, and it is this hopping that renders the two ionic species so mobile in water.

In seeking explanations for the temperature-dependent characteristics, the researchers focused on the speed with which such hops can occur.

Prior research had indicated that two main geometrical arrangements of hydrogen bonds (one associated with each ion) facilitate the hops. The researchers found that one of the arrangements led to significantly slower hops for OH? than for H+ at four degrees Celsius. Being that this is also the temperature of maximum density, the researchers felt that the two phenomena had to be linked. In addition, their results showed that molecules’ hopping behavior changed abruptly at this temperature.

“The study of water’s molecular properties is of intense interest due to its central role in enabling physiological processes and its ubiquitous nature,” says Jerschow, the corresponding author of this study. “The new finding is quite surprising and may enable deeper understanding of water’s properties as well as its role as a fluid in many of nature’s phenomena.”

Tuckerman, who was one of the first researchers to predict the asymmetry in the transport mechanisms and the difference in the hydrogen bond arrangements, says, “It is gratifying to have this clear piece of experimental evidence confirm our earlier predictions. We are currently seeking new ways to exploit the asymmetry between H+ and OH? transport to design new materials for clean energy applications, and knowing that we are starting with a correct model it central to our continued progress.”

A large swath of other research, ranging from the study of enzyme function in the body to understanding how living organisms can thrive in harsh conditions, including sub-freezing temperatures and highly acidic environments, will also be impacted by the team’s findings.

The research was supported by grants from the National Science Foundation (CHE 1710046, CHE-1534374) and partially by the MRSEC Program of the National Science Foundation (DMR-1420073).

Story Source:

Materials provided by New York UniversityNote: Content may be edited for style and length.


Journal Reference:

  1. Emilia V. Silletta, Mark E. Tuckerman, Alexej Jerschow. Unusual Proton Transfer Kinetics in Water at the Temperature of Maximum DensityPhysical Review Letters, 2018; 121 (7) DOI: 10.1103/PhysRevLett.121.076001

 

Source: New York University. “The behavior of water: Scientists find new properties of H2O.” ScienceDaily. ScienceDaily, 13 August 2018. <www.sciencedaily.com/releases/2018/08/180813125244.htm>.

Analysis of tools used to make giant statues could hint at a collaborative society

Date:
August 13, 2018

Source:
Field Museum

Summary:
A new study of the tools used to create Easter Island’s giant statues hints at a society in which people collaborated and shared information.

 

Examples of the Easter Island statues, or moai.
Credit: Dale Simpson, Jr.

 

 

You probably know Easter Island as “the place with the giant stone heads.” This remote island 2,300 miles off the coast of Chile has long been seen as mysterious — a place where Polynesian seafarers set up camp, built giant statues, and then destroyed their own society through in-fighting and over-exploitation of natural resources. However, a new article in the Journal of Pacific Archaeology hints at a more complex story — by analyzing the chemical makeup of the tools used to create the big stone sculptures, archaeologists found evidence of a sophisticated society where the people shared information and collaborated.

“For a long time, people wondered about the culture behind these very important statues,” says Field Museum scientist Laure Dussubieux, one of the study’s authors. “This study shows how people were interacting, it’s helping to revise the theory.”

“The idea of competition and collapse on Easter Island might be overstated,” says lead author Dale Simpson, Jr., an archaeologist from the University of Queensland. “To me, the stone carving industry is solid evidence that there was cooperation among families and craft groups.”

The first people arrived on Easter Island (or, in the local language, Rapa Nui) about 900 years ago. “The founding population, according to oral tradition, was two canoes led by the island’s first chief, Hotu Matu’a,” says Simpson, who is currently on the faculty of the College of DuPage. Over the years, the population rose to the thousands, forming the complex society that carved the statues Easter Island is known for today. These statues, or moai, often referred to as “Easter Island heads,” are actually full-body figures that became partially buried over time. The moai, which represent important Rapa Nui ancestors, number nearly a thousand, and the largest one is over seventy feet tall.

According to Simpson, the size and number of the moai hint at a complex society. “Ancient Rapa Nui had chiefs, priests, and guilds of workers who fished, farmed, and made the moai. There was a certain level of sociopolitical organization that was needed to carve almost a thousand statues,” says Simpson.

Recent excavations of four statues in the inner region of Rano Raraku, the statue quarry, were conducted by Jo Anne Van Tilburg of Cotsen Institute of Archaeology, UCLA and director of the Easter Island Statue Project, along with her Rapa Nui excavation team. To better understand the society that fabricated two of the statues, Simpson, Dussubieux, and Van Tilburg took a detailed look at twenty one of about 1,600 stone tools made of volcanic stone called basalt that had been recovered in Van Tilburg’s excavations. About half of the tools, called toki, recovered were fragments that suggested how they were used.

For Van Tilburg, the goal of the project was to gain a better understanding of how tool makers and statue carvers may have interacted, thus gaining insight into how the statue production industry functioned. “We wanted to figure out where the raw materials used to manufacture the artifacts came from,” explained Dussubieux. “We wanted to know if people were taking material from close to where they lived.”

There are at least three different sources on Easter Island that the Rapa Nui used for material to make their stone tools. The basalt quarries cover twelve square meters, an area the size of two football fields. And those different quarries, the tools that came from them, and the movement between geological locations and archaeological sites shed light on prehistoric Rapa Nui society.

“Basalt is a grayish rock that doesn’t look like anything special, but when you look at the chemical composition of the basalt samples from different sources, you can see very subtle differences in concentrations of different elements,” explains Dussubieux. “Rock from each source is different because of the geology of each site.”

Dussubieux led the chemical analysis of the stone tools. The archaeologists used a laser to cut off tiny pieces of stone from the toki and then used an instrument called a mass spectrometer to analyze the amounts of different chemical elements present in the samples. The results pointed to a society that Simpson believes involved a fair amount of collaboration.

“The majority of the toki came from one quarry complex — once the people found the quarry they liked, they stayed with it,” says Simpson. “For everyone to be using one type of stone, I believe they had to collaborate. That’s why they were so successful — they were working together.”

To Simpson, this level of large-scale cooperation contradicts the popular narrative that Easter Island’s inhabitants ran out of resources and warred themselves into extinction. “There’s so much mystery around Easter Island, because it’s so isolated, but on the island, people were, and still are, interacting in huge amounts,” says Simpson. While the society was later decimated by colonists and slavery, Rapa Nui culture has persisted. “There are thousands of Rapa Nui people alive today — the society isn’t gone,” Simpson explains.

Van Tilburg urges caution in interpreting the study’s results. “The near exclusive use of one quarry to produce these seventeen tools supports a view of craft specialization based on information exchange, but we can’t know at this stage if the interaction was collaborative. It may also have been coercive in some way. Human behavior is complex. This study encourages further mapping and stone sourcing, and our excavations continue to shed new light on moai carving.” In addition to potentially paving the way for a more nuanced view of the Rapa Nui people, Dussubieux notes that the study is important because of its wider-reaching insights into how societies work. “What happens in this world is a cycle, what happened in the past will happen again,” says Dussubieux. “Most people don’t live on a small island, but what we learn about people’s interactions in the past is very important for us now because what shapes our world is how we interact.”

Story Source:

Materials provided by Field MuseumNote: Content may be edited for style and length.


Journal Reference:

  1. Dale Fredrick Simpson Jr. Jo Anne Van Tilburg, Laure Dussubieux. Geochemical and radiometric analyses of archaeological remains from Easter Island’s moai (statue) quarry reveal prehistoric timing, provenance, and use of fine–grain basaltic resourcesJournal of Pacific Archaeology, 2018 [link]

 

Source: Field Museum. “Easter Island’s society might not have collapsed: Analysis of tools used to make giant statues could hint at a collaborative society.” ScienceDaily. ScienceDaily, 13 August 2018. <www.sciencedaily.com/releases/2018/08/180813082757.htm>.

Date:
August 7, 2018

Source:
Lund University

Summary:
Children with allergies have a lower risk of developing complicated appendicitis, according to a new study. The findings could pave the way for new diagnostic tools in the future.

 

Appendicitis definition (stock image).
Credit: © Feng Yu / Fotolia

 

Children with allergies have a lower risk of developing complicated appendicitis, according to a new study from Lund University and Skåne University Hospital in Sweden. The findings, now published in JAMA Pediatrics, could pave the way for new diagnostic tools in the future.

“In a study of all the children who underwent surgery for appendicitis in Lund, Sweden, over the span of a decade, we found that the most common form of allergy, such as allergy to pollen and animal fur, was associated with a three times lower risk of developing complicated appendicitis. The lower risk remained when we adjusted for other parameters known to increase the risk of serious appendicitis, such as lower age and long-lasting symptoms,” says Martin Salö, a researcher at Lund University and physician at Skåne University Hospital.

Appendicitis is widespread among children and young people, and the condition is the most common cause of emergency abdominal surgery in the world.

One third of children affected have a more complicated form of appendicitis which requires a longer hospital stay and sometimes several surgeries. It is not yet clear why some children are affected by this more serious form of appendicitis, nor whether it is possible to prevent it.

One theory holds that complicated appendicitis depends on the body’s immunological response differing to the response in cases of uncomplicated appendicitis. According to this theory, children with allergies have a lower risk of contracting complicated appendicitis, because their immunological response is different from that of non-allergic children. However, this had not been investigated more closely until now.

“The outcome of the study supports the theory that complicated appendicitis has a different immunological development compared to uncomplicated appendicitis. The results also provide clues that we hope can lead to the development of new diagnostic aids such as blood tests,” concludes Martin Salö.

Study in Brief

The study included all children under the age of 15 who underwent surgery for appendicitis at Skåne University Hospital in Lund between 2007 and 2017. In total, 605 children were part of the study.

The researchers compared the outcomes for children with what is known as IgE-mediated allergy (102 children) with those for children without this allergy (503 children). Among the children with IgE-mediated allergy, 19.6% contracted more complicated appendicitis. In the group of children with no IgE-mediated allergy, 46.9% were affected.

Story Source:

Materials provided by Lund UniversityNote: Content may be edited for style and length.


Journal Reference:

  1. Martin Salö, Johanna Gudjonsdottir, Erik Omling, Lars Hagander, Pernilla Stenström. Association of IgE-Mediated Allergy With Risk of Complicated Appendicitis in a Pediatric PopulationJAMA Pediatrics, 2018; DOI: 10.1001/jamapediatrics.2018.1634

 

Source: Lund University. “Link between appendicitis and allergies discovered.” ScienceDaily. ScienceDaily, 7 August 2018. <www.sciencedaily.com/releases/2018/08/180807095106.htm>.

Date:
August 8, 2018

Source:
ESO

Summary:
A glittering host of galaxies populate this rich image taken with ESO’s VLT Survey Telescope, a state-of-the-art 2.6-m telescope designed for surveying the sky in visible light. The features of the multitude of galaxies strewn across the image allow astronomers to uncover the most delicate details of galactic structure.

 

This deep image of the area of sky around the elliptical galaxy NGC 5018 offers a spectacular view of its tenuous streams of stars and gas. These delicate features are hallmarks of galactic interactions, and provide vital clues to the structure and dynamics of early-type galaxies.
Credit: ESO/Spavone et al.

 

 

Whereas ESO’s Very Large Telescope (VLT) can observe very faint astronomical objects in great detail, when astronomers want to understand how the huge variety of galaxies come into being they must turn to a different sort of telescope with a much bigger field of view. The VLT Survey Telescope (VST) is such a telescope. It was designed to explore vast swathes of the pristine Chilean night skies, offering astronomers detailed astronomical surveys of the southern hemisphere.

The powerful surveying properties of the VST led an international team of astronomers to conduct the VST Early-type GAlaxy Survey (VEGAS) [1] to examine a collection of elliptical galaxies in the southern hemisphere [2]. Using the sensitive OmegaCAM detector at the heart of the VST [3], a team led by Marilena Spavone from INAF-Astronomical Observatory of Capodimonte in Naples, Italy, captured images of a wide variety of such galaxies in different environments.

One of these galaxies is NGC 5018, the milky-white galaxy near the centre of this image. It lies in the constellation of Virgo (The Virgin) and may at first resemble nothing but a diffuse blob. But, on closer inspection, a tenuous stream of stars and gas — a tidal tail — can be seen stretching outwards from this elliptical galaxy. Delicate galactic features such as tidal tails and stellar streams are hallmarks of galactic interactions, and provide vital clues to the structure and dynamics of galaxies.

As well as the many elliptical (and a few spiral) galaxies in this remarkable 400-megapixel image, a colourful variety of bright foreground stars in our own Milky Way Galaxy also pepper the image. These stellar interlopers, such as the vividly blue HD 114746 near the centre of the image, are not the intended subjects of this astronomical portrait, but happen to lie between the Earth and the distant galaxies under study. Less prominent, but no less fascinating, are the faint tracks left by asteroids in our own Solar System. Just below NGC 5018, the faint streak left by the asteroid 2001 TJ21 (110423) — captured over several successive observations — can be seen stretching across the image. Further to the right, another asteroid — 2000 WU69 (98603) — left its trace in this spectacular image.

While astronomers set out to investigate the delicate features of distant galaxies millions of light-years from Earth, in the process they also captured images of nearby stars hundreds of light-years away, and even the faint trails of asteroids only light-minutes away in our own Solar System. Even when studying the furthest reaches of the cosmos, the sensitivity of ESO telescopes and dark Chilean skies can offer entrancing observations much closer to home.

Notes

[1] VEGAS is a deep multi-band imaging survey of early-type galaxies carried out with the VLT Survey Telescope (VST), led by Enrichetta Iodice from INAF-Astronomical Observatory of Capodimonte in Naples, Italy.

[2] Elliptical galaxies are also known as early-type galaxies, not because of their age, but because they were once thought to evolve into the more familiar spiral galaxies, an idea now known to be false. Early-type galaxies are characterised by a smooth ellipsoidal shape and usually a lack of gas and active star formation. The bewildering diversity of shapes and types of galaxy is classified into the Hubble Sequence.

[3] OmegaCAM is an exquisitely sensitive detector formed of 32 individual charge coupled devices, and it creates images with 256 million pixels, 16 times greater than the ESA/NASA Hubble Space Telescope’s Advanced Camera for Surveys (ACS. OmegaCAM was designed and built by a consortium including institutes in the Netherlands, Germany and Italy with major contributions from ESO.

Story Source:

Materials provided by ESONote: Content may be edited for style and length.


Journal Reference:

  1. Marilena Spavone et al. VEGAS: A VST Early-type GAlaxy Survey. III. Mapping the galaxy structure, interactions and intragroup light in the NGC 5018 groupAstrophysical Journal, 2018 [link]

 

Source: ESO. “Elliptical elegance in glittering host of galaxies.” ScienceDaily. ScienceDaily, 8 August 2018. <www.sciencedaily.com/releases/2018/08/180808075429.htm>.

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