Two Monumental Milestones Achieved in CT Imaging

Conventional chest CT image (left side) of the human airways compared to the new and improved PCD-CT system (right side). The image produced with the PCD-CT system shows better delineation of the bronchial walls. Preliminary studies showed that the PCD-CT system allowed radiologists to see smaller airways than with standard CT systems.
Image credit: Cynthia McCollough, Mayo Clinic, Rochester, Minnesota.

Two biomedical imaging technologies developed with support from the National Institute of Biomedical Imaging and Bioengineering (NIBIB) have been cleared for clinical use by the Food and Drug Administration (FDA). Both technologies offer advances in computed tomography (CT).

In one of these developments, project lead Cynthia McCollough, Ph.D., director of Mayo Clinic’s CT Clinical Innovation Center and her team helped develop the first photon-counting detector (PCD)-CT system, which is superior to current CT technology. CT imaging has been an immense clinical asset for diagnosing many diseases and injuries. However, since its introduction into the clinic in 1971, the way that the CT detector converts x-rays to electrical signals has remained essentially the same. Photon-counting detectors operate using a fundamentally different mechanism than any prior CT detector ever has.

“This is the first major imaging advancement cleared by the FDA for CT in a decade,” stated Behrouz Shabestari, Ph.D., director of the division of Health Informatics Technologies. “The impact of this development will be far-reaching and provide clinicians with more detailed information for medical diagnoses.”

A CT scan is obtained when an x-ray beam rotates around a patient, allowing x-rays to pass through the patient. As the x-rays leave the patient a picture is taken by a detector and the information is transmitted to a computer for further processing. “Standard CT detectors use a two-step process, where x-rays are turned into light and then light is converted to an electrical signal,” explained Cynthia McCollough. “The photon-counting detector uses a one-step process where the x-ray is immediately transformed into an electrical signal.”

AI could help patients with chronic pain avoid opioids

Image by Andrea from Pixabay

Cognitive behavioral therapy is an effective alternative to opioid painkillers for managing chronic pain. But getting patients to complete those programs is challenging, especially because psychotherapy often requires multiple sessions and mental health specialists are scarce.

A new study suggests that pain CBT supported by artificial intelligence renders the same results as guideline-recommended programs delivered by therapists, while requiring substantially less clinician time, making this therapy more accessible.

“Chronic pain is incredibly common: back pain, osteoarthritis, migraine headaches and more. Because of pain, people miss work, develop depression, some people drink more alcohol than is healthy, and chronic pain is one of the main drivers of the opioid epidemic,” said John Piette, a professor at the University of Michigan’s School of Public Health and senior research scientist at the Veterans Administration.

“We’re very excited about the results of this study, because we were able to demonstrate that we can achieve pain outcomes that are at least as good as standard cognitive behavioral therapy programs, and maybe even better. And we did that with less than half the therapist time as guideline-recommended approaches.”

Traditionally, CBT is delivered by a therapist in 6 to 12 weekly in-person sessions that target patients’ behaviors, help them cope mentally and assist them in regaining functioning.

Synthetic genetic circuits that could help plants adapt to pressures from climate change

The activity of synthetic genetic circuits that process the presence or absence of specific signals in plant leaves was measured in high throughput by placing leaf punches in 96-well plates. When the correct combinations of inputs are delivered to leaves, they fluoresce green, and the fluorescence can be measured using a plate reader.
Image credit: Jennifer Brophy

Using synthetic genes, researchers at Stanford have been able to modify the root structures of plants. Their work could make crops more efficient at gathering nutrients and water, and more resilient to increasing pressures from climate change.

Increasingly, global food production is being threatened by the effects of climate change. As floods, droughts, and extreme heat waves become more common, crops need to be able to adapt faster than ever.

Researchers at Stanford University are working on ways to manipulate biological processes in plants to help them grow more efficiently and effectively in a variety of conditions. Jennifer Brophy, an assistant professor of bioengineering, and her colleagues have designed a series of synthetic genetic circuits that allow them to control the decisions made by different types of plant cells. In a paper published recently in Science, they used these tools to grow plants with modified root structures. Their work is the first step in designing crops that are better able to collect water and nutrients from the soil and provides a framework for designing, testing, and improving synthetic genetic circuits for other applications in plants.

“Our synthetic genetic circuits are going to allow us to build very specific root systems or very specific leaf structures to see what is optimal for the challenging environmental conditions that we know are coming,” Brophy said. “We’re making the engineering of plants much more precise.”

Brightest stars in the night sky can strip planets to their rocky cores

Artist’s concept of a Neptune-sized planet, left, around a blue, A-type star. UC Berkeley astronomers have discovered a hard-to-find gas giant around one of these bright, but short-lived, stars, right at the edge of the hot Neptune desert where the star’s strong radiation likely strips any giant planet of its gas.
 Image credit: Steven Giacalone, UC Berkeley

Over the last 25 years, astronomers have found thousands of exoplanets around stars in our galaxy, but more than 99% of them orbit smaller stars — from red dwarfs to stars slightly more massive than our sun, which is considered an average-sized star.

Few have been discovered around even more massive stars, such as A-type stars — bright blue stars twice as large as the sun — and most of the exoplanets that have been observed are the size of Jupiter or larger. Some of the brightest stars in the night sky, such as Sirius and Vega, are A-type stars.

University of California, Berkeley, astronomers now report a new, Neptune-sized planet — called HD 56414 b — around one of these hot-burning, but short-lived, A-type stars and provide a hint about why so few gas giants smaller than Jupiter have been seen around the brightest 1% of stars in our galaxy.

Current exoplanet detection methods most easily find planets with short, rapid orbital periods around their stars, but this newly found planet has a longer orbital period than most discovered to date. The researchers suggest that an easier-to-find Neptune-sized planet sitting closer to a bright A-type star would be rapidly stripped of its gas by the harsh stellar radiation and reduced to an undetectable core.

Breast cancer cells use forces to open up channels through tissue

An illustrated microscope view of a 3D culture of cancer cells. A cancer cell generates forces (in red) moving the tissue material farther. The new technique detects the material movement to compute cellular forces.
Image Credit: Juho Pokki/Aalto University

Research to understand how cancers grow and spread has conventionally been done on two-dimensional, flat cultures of cells, which is very different to the three-dimensional structure of cells in the body. 3D cell cultures that incorporate tissue material have been developed, but the methods to measure how cancer cells use forces to spread have been lacking.

Now, researchers have developed a new method for 3D culture to accurately quantify how cancer cells generate forces to spread within tissue. ‘We have applied the method for investigation of early progression of breast cancer,’ says Juho Pokki, a principal investigator at Aalto University who led the research.

This study, a collaboration between scientists at Aalto University and Stanford University, was published in the journal Nano Letters.

Mini donkey gets big boost from pacemaker

Veterinarians at Cornell prepare miniature donkey Nix for her pacemaker surgery.
Credit: Carol Jennings/CVM 

Nix, a miniature donkey with a potentially fatal heart condition, is on the mend after a successful pacemaker implantation by veterinarians at the Cornell University Hospital for Animals – the first surgery of its kind in a large animal species at Cornell.

“It was either do nothing and Nix would continue to get worse and possibly have a painful death – or the pacemaker,” said Mindy Lockwood of Canandaigua, New York, who owns Nix with her husband, Carlton.

Nix’s collapsing episodes and overall lethargy began in the fall of 2020 when she was only a few months old. Her regular veterinarian, Dr. Joan Ayers of Genesee Valley Veterinary Hospital, assessed her condition in consultation with the Lockwoods and Dr. Barbara Delvescovo, clinical fellow in the Section of Large Animal Medicine at Cornell.

In February of this year, Nix’s condition worsened. The Lockwoods saw that Nix was falling again, this time from a standing position, and she staggered even more while walking. “When she fell, she was dazed for a few seconds and then would get back up. Several times she fell and rolled out of the pasture fence, which caused us even more concern for her safety,” Carlton Lockwood said.

Uncovering the Past: Researchers Create 3D Images of Fossils

Aase mounts one of the fossils in the X-ray microscope for imaging.
Credit: Idaho National Laboratory

Idaho National Laboratory is perhaps best known for innovative research that helps shape the clean energy economies of today and tomorrow – and for good reason. But while much of the laboratory’s work is focused on building a sustainable future, INL is also doing its part to preserve the past.

INL researchers recently imaged several fossils using a powerful X-ray microscope. The 3D images will be used to create exhibits for Wyoming’s Fossil Butte National Monument and help experts gain insight into the origins of these and other relics.

The fossils, found in private quarries around Wyoming, were imaged using a technique known as X-ray microscopy. At INL, researchers typically use high-resolution X-ray microscopy to view specimens – such as samples of irradiated nuclear fuel — at a level of detail not possible with conventional microscopes. The depth and granularity afforded by this technique will help paleontologists learn a great deal about these fossils —including an unknown object resembling an insect egg case or pea pod — and the conditions under which they formed.

“You can see the limestone layers as well as submillimeter and thinner organic materials that have been compressed into waxy, pre-petroleum substances around the specimen,” said Arvid Aase, a paleontologist and the museum curator at Fossil Butte National Monument. “These incredibly detailed images will help us determine the organism’s taxonomy and reveal information about its fossilization process, such as how long it was laying on the bottom of the lake covered in microbes before getting buried by limestone.”

The fossilization process may have occurred over a period of months, though the timing still remains unknown, he added.

Northwestern rocket to image supernova remnant

A Northwestern University astrophysics team is aiming for the stars — well, a dead star, that is.

On Aug. 21, the NASA-funded team will launch its “Micro-X” rocket from White Sands Missile Range in southern New Mexico. The rocket will spend 15 minutes in space — just enough time to snap a quick image of supernova remnant Cassiopeia A, a star in the Cassiopeia constellation that exploded approximately 11,000 light-years away from Earth. Then, the rocket will parachute back to Earth, landing in the desert — about 45 miles from the launchpad — where the Northwestern team will recover its payload.

Short for “high-resolution microcalorimeter X-ray imaging rocket,” the Micro-X rocket will carry a superconductor-based X-ray imaging spectrometer that is capable of measuring the energy of each incoming X-ray from astronomical sources with unprecedented accuracy.

“The supernova remnant is so hot that most of the light it emits is not in the visible range,” said Northwestern’s Enectali Figueroa-Feliciano, who leads the project. “We have to use X-ray imaging, which isn’t possible from Earth because our atmosphere absorbs X-rays. That’s why we have to go into space. It’s like if you jumped into the air, snapped a photo just as your head peeked above the atmosphere and then landed back down.”

Figueroa-Feliciano is a professor of physics and astronomy in the Weinberg College of Arts and Sciences and a member of Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). He advised a team of seven graduate students, postdoctoral fellows and post-baccalaureate researchers, who spent the past decade building and testing the rocket.

MIT scientists discover new antiviral defense system in bacteria

A team led by researchers at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT has discovered that organisms across all three domains of life — bacteria, archaea, and eukaryotes (which includes plants and animals) — use pattern recognition of conserved viral proteins to defend against pathogens.
Credits: Image courtesy of Feng Zhang

Bacteria use a variety of defense strategies to fight off viral infection, and some of these systems have led to groundbreaking technologies, such as CRISPR-based gene-editing. Scientists predict there are many more antiviral weapons yet to be found in the microbial world.

A team led by researchers at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT has discovered and characterized one of these unexplored microbial defense systems. They found that certain proteins in bacteria and archaea (together known as prokaryotes) detect viruses in surprisingly direct ways, recognizing key parts of the viruses and causing the single-celled organisms to commit suicide to quell the infection within a microbial community. The study is the first time this mechanism has been seen in prokaryotes and shows that organisms across all three domains of life — bacteria, archaea, and eukaryotes (which includes plants and animals) — use pattern recognition of conserved viral proteins to defend against pathogens.

The study appears in Science.

Large number of stem cell lines carry significant DNA damage, say researchers

Our Sun Credit:
Alexas Fotos / Public Domain

DNA damage caused by factors such as ultraviolet radiation affect nearly three-quarters of all stem cell lines derived from human skin cells, say Cambridge researchers, who argue that whole genome sequencing is essential for confirming if cell lines are usable.

Stem cells are a special type of cell that can be programmed to become almost any type of cell within the body. They are currently used for studies on the development of organs and even the early stages of the embryo.

Increasingly, researchers are turning to stem cells as ways of developing new treatments, known as cell-based therapies. Other potential applications include programming stem cells to grow into nerve cells to replace those lost to neurodegeneration in diseases such as Parkinson’s.

Originally, stem cells were derived from embryos, but it is now possible to derive stem cells from adult skin cells. These so-called induced pluripotent stem cells (iPSCs) have now been generated from a range of tissues, including blood, which is increasing in popularity due to its ease of derivation.

However, researchers at the University of Cambridge and Wellcome Sanger Institute have discovered a problem with stem cell lines derived from both skin cells and blood. When they examined the genomes of the stem cell lines in detail, they found that nearly three quarters carried substantial damage to their DNA that could compromise their use both in research and, crucially, in cell-based therapies. Their findings represent the largest genetic study to date of iPSCs and are published today in Nature Genetics.

DNA is made up of three billion pairs of nucleotides, molecules represented by the letters A, C, G and T. Over time, damage to our DNA, for example from ultraviolet radiation, can lead to mutations – a letter C might change to a letter T, for example. ‘Fingerprints’ left on our DNA can reveal what is responsible for this damage. As these mutations accumulate, they can have a profound effect on the function of cells and in some cases lead to tumors.