Monthly Archives: February 2020

How To Early Detect Prostate Cancer

For the first time, a team of scientists at the University of Central Florida has created functional nanomaterials with hollow interiors that can be used to create highly sensitive biosensors for early cancer detection. Xiaohu Xia, an assistant professor of chemistry with a joint appointment in the NanoScience Technology Center, and his team developed the new method and recently published their work in the journal ACS Nano.

These advanced hollow nanomaterials hold great potential to enable high-performance technologies in various areas,” says Xia. “Potentially we could be talking about a better and less expensive diagnostic tool, sensitive enough to detect biomarkers at low concentrations, which could make it invaluable for early detection of cancers and infectious diseases.”

Because hollow nanomaterials made of gold and silver alloys display superior optical properties, they could be particularly good for developing better test strip technology, similar to over-the-counter pregnancy tests. Currently the technology used to indicate positive or negative symbols on the test stick is not sensitive enough to pick up markers that indicate certain types of cancer. But Xia’s new method of creating hollow nanomaterials could change that. More advance warning could help doctors save more lives.

In conventional test strips, solid gold nanoparticles are often used as labels, where they are connected with antibodies and specifically generate color signal due to an optical phenomenon called localized surface plasmon resonance. Under Xia’s technique, metallic nanomaterials can be crafted with hollow interiors. Compared to the solid counterparts, these hollow nanostructures possess much stronger LSPR activities and thus offer more intense color signal. Therefore, when the hollow nanomaterials are used as labels in test strips they can induce sensitive color change, enabling the strips to detect biomarkers at lower concentrations.

Test-strip technology gets upgraded by simply replacing solid gold nanoparticles with the unique hollow nanoparticles, while all other components of a test strip are kept unchanged,” says Xia. “Just like the pregnancy test, the new test strip can be performed by non-skilled persons, and the results can be determined with the naked eye without the need of any equipment. These features make the strip extremely suitable for use in challenging locations such as remote villages.”

The UCF study focused on prostate-specific antigen, a biomarker for prostate cancer. The new test strip based on hollow nanomaterials was able to detect PSA as low as 0.1 nanogram per milliliter (ng/mL), which is sufficiently sensitive for clinical diagnostics of prostate cancer. The published study includes electron microscope images of the metallic hollow nanomaterials.

“I hope that by providing a general and versatile platform to engineer functional hollow nanomaterials with desired properties, new research with the potential for other applications beyond biosensing can be launched,” Xia says.

Source: https://www.ucf.edu/

How To Uncloak Cancer Cells And Reveal Them To The Immune System

Scientists at Johns Hopkins report they have designed and successfully tested an experimental, super small package able to deliver molecular signals that tag implanted human cancer cells in mice and make them visible for destruction by the animals’ immune systems. The new method was developed, say the researchers, to deliver an immune system “uncloaking” device directly to cancer cells.

Conventional immune therapies generally focus on manipulating patients’ immune system cells to boost their cancer-killing properties or injecting drugs that do the same but often have toxic side effectsA hallmark of cancer biology is a tumor cell’s ability to essentially hide from the immune system cells whose job is to identify and destroy cancer cells. Current cellular immunotherapies, notably CAR-T, require scientists to chemically alter and enhance a patient’s own harvested immune system T-cells — an expensive and time-consuming process, say the researchers. Other weapons in the arsenal of immunotherapies are drugs, including so-called checkpoint inhibitors, which have broad effects and often lead to unwanted immune-system-associated side effects, including damage to normal tissue.

By contrast, the Johns Hopkins team sought an immune system therapy that can work like a drug but that also individually engineers a tumor and its surrounding environment to draw the immune system cells to it, says Jordan Green, Ph.D, professor of biomedical engineering at the Johns Hopkins University School of Medicine.

A microscopic image of the nanoparticles used in the study. The black scale bar is 100 nm in size
 And our process happens entirely within the body,” Green says, “requiring no external manipulation of a patient’s cells.

To develop the new system, Green and his team, including Stephany Tzeng, Ph.D., a research associate in the Department of Biomedical Engineering at Johns Hopkins, took advantage of a cancer cell’s tendency to internalize molecules from its surroundings. “Cancer cells may be easier to directly genetically manipulate because their DNA has gone haywire, they divide rapidly, and they don’t have the typical checks and balances of normal cells,” says Green.

The team created a polymer-based nanoparticle — a tiny case that slips inside cells. They guided the nanoparticles to cancer cells by injecting them directly into the animals’ tumors. “The nanoparticle method we developed is widely applicable to many solid tumors despite their variability on an individual and tumor type level,” says Green, also a member of the Johns Hopkins Kimmel Cancer Center. Once inside the cell, the water-soluble nanoparticle slowly degrades over a day. It contains a ring of DNA, called a plasmid, that does not integrate into the genome and is eventually degraded as the cancer cell divides, but it stays active long enough to alter protein production in the cell.

The additional genomic material from the plasmid makes the tumor cells produce surface proteins called 4-1BBL, which work like red flags to say, “I’m a cancer cell, activate defenses.” The plasmid also forces the cancer cells to secrete chemicals called interleukins into the space around the cells. The 4-1BBL tags and interleukins are like magnets to immune system cells, and they seek to kill the foreign-looking cancer cells.

Results of the proof-of-concept experiments were published online in the Proceedings of the National Academy of Sciences.

Source: https://www.hopkinsmedicine.org/

AI Detects Visual Signs Of Covid-19

Zhongnan Hospital of Wuhan University in Wuhan, China, is at the heart of the outbreak of Covid-19, the disease caused by the new coronavirus SARS-CoV-2 that has shut down cities in China, South Korea, Iran, and Italy. That’s forced the hospital to become a testbed for how quickly a modern medical center can adapt to a new infectious disease epidemic.

One experiment is underway in Zhongnan’s radiology department, where staff are using artificial intelligence software to detect visual signs of the pneumonia associated with Covid-19 on lung CT scan images. Haibo Xu, professor and chair of radiology at Zhongnan Hospital, says the software helps overworked staff screen patients and prioritize those most likely to have Covid-19 for further examination and testing 

Detecting pneumonia on a scan doesn’t alone confirm a person has the disease, but Xu says doing so helps staff diagnose, isolate, and treat patients more quickly. The software “can identify typical signs or partial signs of Covid-19 pneumonia,” he wrotel. Doctors can then follow up with other examinations and lab tests to confirm a diagnosis of the disease. Xu says his department was quickly overwhelmed as the virus spread through Wuhan in January.

The software in use at Zhongnan was created by Beijing startup Infervision, which says  its Covid-19 tool has been deployed at 34 hospitals in China and used to review more than 32,000 cases. The startup, founded in 2015 with funding from investors including early Google backer Sequoia Capital, is an example of how China has embraced applying artificial intelligence to medicine.

China’s government has urged development of AI tools for healthcare as part of sweeping national investments in artificial intelligence. China’s relatively lax rules on privacy allow companies such as Infervision to gather medical data to train machine learning algorithms in tasks like reading scans more easily than US or European rivals.

Infervision created its main product, software that flags possible lung problems on CT scans, using hundreds of thousands of lung images collected from major Chinese hospitals. The software is in use at hospitals in China, and being evaluated by clinics in Europe, and the US, primarily to detect potentially cancerous lung nodulesInfervision began work on its Covid-19 detector early in the outbreak after noticing a sudden shift in how existing customers were using its lung-scan-reading software. In mid-January, not long after the US Centers for Disease Control advised against travel to Wuhan due to the new disease, hospitals in Hubei Province began employing a previously little-used feature of Infervision’s software that looks for evidence of pneumonia, says CEO Kuan Chen. “We realized it was coming from the outbreak,” he says.

Source: https://www.wired.com/

How To Direct Nanoparticles Straight To Tumors

Modern anticancer therapies aim to attack tumor cells while sparing healthy tissue. An interdisciplinary team of researchers at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and FU Berlin has made important progress in this area: the scientists have produced tiny nanoparticles that are designed to specifically target cancer cells. They can navigate directly to the tumor cells and visualize those using advanced imaging techniques. Both in petri dishes and animal models, the scientists were able to effectively guide the nanoparticles to the cancer cells. The next step is to combine the new technique with therapeutic approaches.The HZDR researchers start out with tiny, biocompatible nanoparticles made of so-called dendritic polyglycerols that serve as carrier molecules.

Radiologic technician and Patient being scanned and diagnosed on CT (computed tomography) scanner in hospital

An interdisciplinary team has modified biocompatible nanoparticles with an antibody fragment, which binds specifically to a protein overexpressed by certain types of cancer cells. By combining the tiny particles with a diagnostic radionuclide, it is, thus, possible to detect and characterize tumor cells via PET.

We can modify these particles and introduce various functions,” explains Dr. Kristof Zarschler, research associate at HZDR’s Institute of Radiopharmaceutical Cancer Research. “For example, we can attach an antibody fragment to the particle that specifically binds to cancer cells. This antibody fragment is our targeting moiety that directs the nanoparticle to the tumor.”

The target of the modified nanoparticles is an antigen known as EGFR (epidermal growth factor receptor). In certain types of cancer, such as breast cancer or head and neck tumors, this protein is overexpressed on the surface of the cells. “We were able to show that our designed nanoparticles preferentially interact with the cancer cells via these receptors,” confirms Dr. Holger Stephan, leader of the Nanoscalic Systems Group at HZDR. “In control tests with similar nanoparticles that had been modified with an unspecific antibody, significantly fewer nanoparticles accumulated at the tumor cells.

The scientists intensively studied the nanoparticles’ behavior both in cell cultures and in an animal model. For this purpose, they provided the nanoparticles with additional reporter characteristics, as Kristof Zarschler explains: “We used two complementary possibilities. In addition to the antibodies, we attached dye molecules and radionuclides to the nanoparticles. The dye molecule emits in the near infrared spectrum that penetrates the tissue and can be visualized with an appropriate microscope. The dye thus reveals where exactly the nanoparticles are located.” The radionuclide, copper-64, fulfils a similar purpose. It emits radiation that is detected by a PET scanner (positron emission tomography). The signals can then be converted into a three-dimensional image that visualizes the distribution of the nanoparticles in the organism.

Using these imaging techniques, researchers have been able to show that nanoparticle accumulation in the tumor tissue reaches maximum two days after administration to mice. The labelled nanoparticles are subsequently eliminated via the kidneys without being a burden for the body. “They are apparently ideal in size and properties,” says Holger Stephan. “Smaller particles are filtered out of the blood in just a few hours and thus only have a short-term impact. If, on the other hand, the particles are too big, they accumulate in the spleen, liver or lungs and cannot be removed from the body via the kidneys and bladder.” The interplay between the nanoparticles with an exact size of three nanometers and the attached antibody fragments evidently has a positive influence on the distribution and retention of the antibody in the organism as well as on its excretion profile.

Source: https://www.hzdr.de/

Nano-Transistor From DNA-like Material

Computer chips use billions of tiny switches, called transistors, to process information. The more transistors on a chip, the faster the computer. A material shaped like a one-dimensional DNA helix might further push the limits on a transistor’s size. The material comes from a rare earth element called tellurium.

Researchers found that the material, encapsulated in a nanotube made of boron nitride, helps build a field-effect transistor with a diameter of two nanometers. Transistors on the market are made of bulkier silicon and range between 10 and 20 nanometers in scale.  Engineers at Purdue University performed the work in collaboration with Michigan Technological University, Washington University in St. Louis, and the University of Texas at Dallas.

Over the past few years, transistors have been built as small as a few nanometers in lab settings. The goal is to build transistors the size of atomsPeide Ye’s lab at Purdue is one of many research groups seeking to exploit materials much thinner than silicon to achieve both smaller and higher-performing transistors.

These silver, wiggling lines are strings of atoms in tellurium behaving like DNA. Researchers have not seen this behavior in any other material.

This tellurium material is really unique. It builds a functional transistor with the potential to be the smallest in the world,” said Ye, Purdue’s Richard J. and Mary Jo Schwartz Professor of Electrical and Computer Engineering.

The research is published in the journal Nature Electronics.

Source: https://www.purdue.edu/

Lifelong Antisocial Behaviour Linked To Brain Structure

People who engage in persistent antisocial behaviour long after adolescence have characteristic differences in brain structure, finds a new UCL-led study.

The study, published in The Lancet Psychiatry, identified brain differences between people who engage in antisocial behaviour – such as theft, aggression, violence, bullying, lying, or repeated failure to take care of work or school responsibilities – only during adolescence and those who persist throughout adulthood.

Our findings support the idea that, for the small proportion of individuals with life-course-persistent antisocial behaviour, there may be differences in their brain structure that make it difficult for them to develop social skills that prevent them from engaging in antisocial behaviour. These people could benefit from more support throughout their lives,” said lead author Dr Christina Carlisi (UCL Psychology & Language Sciences).

Most people who exhibit antisocial behaviour primarily do so only in adolescence, likely as a result of navigating socially difficult years, and these individuals do not display structural brain differences. It is also these individuals who are generally capable of reform and go on to become valuable members of society.”

Previous studies have found that antisocial behaviour is most prevalent in adolescence, before people mature into adulthood, while a smaller number of people will continue with antisocial behaviour over multiple decades.

Source: https://www.ucl.ac.uk/

Why Are HIV Drugs Being Used to Treat the Coronavirus?

On Tuesday, the Japanese government announced it will begin clinical trials to test treatments for the deadly new coronavirus that’s engulfed China and spread to over two dozen countries. Rather than new drugs, they’ll be studying existing medications already used to treat HIV and other viral diseases. But why exactly are researchers hopeful that these drugs can be repurposed for the new coronavirus, and how likely are they to work?

The new coronavirus, recently named SARS-CoV-2 due to its close genetic ties to the SARS coronavirus, is made out of RNA. Other RNA viruses include the ones that cause Ebola, hepatitis C, and yes, HIV/AIDS.

RNA viruses come in all shapes and sizes, and those that infect humans can do so in different ways. But many of the drugs that go after HIV and the hepatitis C virus broadly target weaknesses found in all sorts of viruses. The approved hepatitis C drug ribavirin, for instance, interferes with something called the RNA-dependent RNA polymerase, an enzyme essential for many virusesincluding coronaviruses—to produce more of themselves inside a cell. HIV drugs like lopinavir inhibit other enzymes that allow viruses to break down certain proteins, which cripples their ability to infect cells and replicate.

Broad antiviral drugs like lopinavir should be able to work against SARS-CoV-2scientists theorize. And there’s already some circumstantial evidence they do. Some of these drugs have been successfully tested out for SARS and MERS, for instance, two other nasty coronaviruses that have emerged in recent years.

In January, the Chinese government announced a trial of 41 patients in Wuhan that would use a combination therapy of lopinavir and another HIV drug, ritonavir. In February, the Chinese government also began a trial using an experimental drug that’s been tested out for Ebola, called remdesivir.

Remdesivir has already been deployed during this outbreak, with seemingly impressive results so far. Last month, the first documented U.S. patient with the virus was treated with remdesivir, following a week of worsening symptoms that had developed into full-blown pneumonia. Within a day of receiving the drug through an IV, though, the man’s symptoms started to improve, and he was eventually released from the hospital.

But one case does not a surefire treatment make. And even if remdesivir or other drugs do prove effective against SARS-CoV-2, they’ll only play a small part in stopping this current outbreak from getting worse. Most cases of COVID-19 (the official name of the disease caused by SARS-COV-2) are still mild and won’t be helped much by antiviral drugs. In terms of preventing the next pandemic, it’s more important to keep people from getting the virus at all, rather than finding drugs to treat them once they do.

Source: https://gizmodo.com/

How To Recycle Greenhouse Gases into Fuel and Hydrogen

Scientists have taken a major step toward a circular carbon economy by developing a long-lasting, economical catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas, and other chemicals. The results could be revolutionary in the effort to reverse global warming, according to the researchers. The study was published in Science.

Newly developed catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas and other chemicals

We set out to develop an effective catalyst that can convert large amounts of the greenhouse gases carbon dioxide and methane without failure,” said Cafer T. Yavuz, paper author and associate professor of chemical and biomolecular engineering and of chemistry at KAIST (Korea).

The catalyst, made from inexpensive and abundant nickel, magnesium, and molybdenum, initiates and speeds up the rate of reaction that converts carbon dioxide and methane into hydrogen gas. It can work efficiently for more than a month.

This conversion is called ‘dry reforming’, where harmful gases, such as carbon dioxide, are processed to produce more useful chemicals that could be refined for use in fuel, plastics, or even pharmaceuticals. It is an effective process, but it previously required rare and expensive metals such as platinum and rhodium to induce a brief and inefficient chemical reaction.

Other researchers had previously proposed nickel as a more economical solution, but carbon byproducts would build up and the surface nanoparticles would bind together on the cheaper metal, fundamentally changing the composition and geometry of the catalyst and rendering it useless.

The difficulty arises from the lack of control on scores of active sites over the bulky catalysts surfaces because any refinement procedures attempted also change the nature of the catalyst itself,” Yavuz said.

The researchers produced nickel-molybdenum nanoparticles under a reductive environment in the presence of a single crystalline magnesium oxide. As the ingredients were heated under reactive gas, the nanoparticles moved on the pristine crystal surface seeking anchoring points. The resulting activated catalyst sealed its own high-energy active sites and permanently fixed the location of the nanoparticles — meaning that the nickel-based catalyst will not have a carbon build up, nor will the surface particles bind to one another.

It took us almost a year to understand the underlying mechanism,” said first author Youngdong Song, a graduate student in the Department of Chemical and Biomolecular Engineering at KAIST. “Once we studied all the chemical events in detail, we were shocked.”

The researchers dubbed the catalyst Nanocatalysts on Single Crystal Edges (NOSCE). The magnesium-oxide nanopowder comes from a finely structured form of magnesium oxide, where the molecules bind continuously to the edge. There are no breaks or defects in the surface, allowing for uniform and predictable reactions.

Our study solves a number of challenges the catalyst community faces,” Yavuz said. “We believe the NOSCE mechanism will improve other inefficient catalytic reactions and provide even further savings of greenhouse gas emissions.

Source: https://news.kaist.ac.kr/

Nanoscale Device Acts Like The Brain’s Visual Cortex To Directly See Things

In a new study published in February 2020 in the journal Science Advances, researchers report the development of a nanoscale device that acts like the brain’s visual cortex to directly see things in its path. The scientists created a new superstructure through the use of two nanomaterials in tandem that could help to make a machine that uses AI to simulate a human mind‘s function.

This is a baby step toward developing neuromorphic computers, that can simultaneously process and memorize information. At some time in the future, this invention may help to make robots that can think like humans,” researcher Jayan Thomas says,  The big advantage of the current approach is in its saving of energy for processing as well as the time required for computation.

 

Another researcher, Tania Roy, predicted that the new technology might be applied to drones that can fly unaided to remote locations to find people in various dangerous situations. The problem with current drones is, she says, because “These drones need connectivity to remote servers to identify what they scan with their camera eye. Our device makes this drone truly autonomous because it can see just like a human.

With earlier research, scientists succeeded in making a camera that can create an image of what is observed, and then upload it for processing and image recognition to a server. The current device, she says, not only sees the image but also instantly recognizes it.

According to the researchers, this could also be extremely valuable for defense applications, such as helping soldiers see better on a battlefield. Another potential advantage is that, according to the co-first author Sonali Das, “Our device can sense, detect and reconstruct an image along with extremely low power consumption, which makes it capable for long-term deployment in field applications.”

The scientists tested out the device in face recognition experiments. These were only meant to be tests to check out how well the neuromorphic computing helped the machine to see objects. Describing these as preliminary, Thomas says they wanted to assess the optoelectronic device. “Since our device mimics vision-related brain cells, facial recognition is one of the most important tests for our neuromorphic building block.”

Source: https://www.news-medical.net/

AI Predicts Heart Attacks

In a study published Feb. 14 in Circulation, researchers in the U.K. and the U.S. report that an AI program can reliably predict heart attacks and strokes. Kristopher Knott, a research fellow at the British Heart Foundation, and his team conducted the largest study yet involving cardiovascular magnetic resonance imaging (CMR) and AI. CMR is a scan that measures blood flow to the heart by detecting how much of a special contrast agent heart muscle picks up; the stronger the blood flow, the less likely there will be blockages in the heart vessels. Reading the scans, however, is time consuming and laborious; and it’s also more qualitative than quantitative, says Knott, subject to the vagaries of the human eyes and brain. To try to develop a more qualitative tool, Knott and his colleagues trained an AI model to read scans and learn to detect signs of compromised blood flow.

When they tested the technology on the scans of more than 1,000 people who needed CMR because they either at risk of developing heart disease or had already been diagnosed, they found the AI model worked pretty well at selecting out which people were more likely to go on to have a heart attack or stroke, or die from one. The study compared the AI-based analyses to health outcomes from the patients, who were followed for about 20 months on average. The researchers discovered that for every 1 ml/g/min decrease in blood flow to the heart, the risk of dying from a heart event nearly doubled, and the risk of having a heart attack, stroke or other event more than doubled.

Rather than a qualitative view of blood flow to the heart muscle, we get a quantitative number,” he says. “And from that number, we’ve shown that we can predict which people are at higher risk of adverse events.”

The study confirmed that CMR is a strong marker for risk of heart problems, but did not prove that the scans could actually be used to guide doctors’ decisions about which people are at higher risk. For that, more studies need to be done that document whether treating poor blood flow—with available medication or procedures—in people with decreased flow as predicted by the AI model, can reduce or eliminate heart attacks and strokes.

Source: https://time.com/