. Scientific Frontline

Tuesday, March 22, 2022

A robot small enough to explore the lungs

The image shows a life-size model of part of a bronchial tree built from anatomical data. A section of the magnetic tentacle robot is seen on the right.
Credit: University of Leeds

Engineers and scientists have paved the way for a robot that can reach some of the smallest bronchial tubes in the lungs – to take tissue samples or deliver cancer therapy.

Known as a magnetic tentacle robot, it measures just 2 millimeters in diameter, about twice the size of the tip of a ballpoint pen.

Magnets on the outside of the patient will be used to guide the magnetic tentacle robot into place.

The device has been developed by a team of engineers, scientists and clinicians based at the STORM Lab at Leeds, which is pioneering the use of robotic systems to assist in endoscopy and catheter procedures, where a fine tube is inserted into the body.

The researchers have published their findings in the journal Soft Robotics.

The proof of concept they have developed was based on laboratory tests involving a 3D replica of a bronchial tree modelled from anatomical data. The next phase of the research will investigate the effectiveness of the device in navigating lungs taken from a cadaver.

No return to normal, permanent drought or wet conditions ahead

Credit: Oleksandr Sushko

Many regions of the world will enter nearly permanent drought or pluvial (wet) conditions in the coming decades, according to researchers from half a dozen institutions, including the University of Hawaiʻi at Mānoa, who investigated what the future might hold in terms of rainfall and soil moisture. The findings, published in Proceedings of the National Academy of Sciences, reveal the importance of rethinking how these events are classified as well as how communities adapt to a changing environment.

In some areas of the western United States, for instance, conditions have blown past severe and extreme drought into exceptional drought. But rather than add more superlatives to the descriptions, it could be time to reconsider the very definition of drought.

“When we talk about being in a drought, the presumption is that eventually the drought will end, and conditions will return to normal,” said Samantha Stevenson, lead author of the study, assistant professor at the University of California, Santa Barbara and former postdoctoral fellow at UH Mānoa’s School of Ocean and Earth Science and Technology (SOEST). “But if we’re never returning to normal, then we need to adapt all of the ways that we manage water with the expectation that normal will continually be drier and drier every year.”

‘Junk DNA’ key to controlling fear

A piece of “junk DNA” could be the key to extinguishing fear-related memories for people struggling with post-traumatic stress disorder (PTSD) and phobia, according to a study from The University of Queensland.

An international research project, led by the Queensland Brain Institute’s Associate Professor Timothy Bredy, discovered the new gene while investigating how the genome responds to traumatic experiences.

“Until recently, scientists thought the majority of our genes were made up of junk DNA, which essentially didn’t do anything.” Dr Bredy said.

“But when researchers began to explore these regions, they realized that most of the genome is active and transcribed.”

Using a powerful new sequencing approach, Dr Bredy’s team identified 433 long non-coding RNAs from relatively unknown regions of the human genome.

“The technology is a really interesting way to zero in on sites within the genome that would otherwise be masked,” Dr Bredy said.

“It’s like harnessing the power of the Hubble Telescope to peer into the unknown of the brain.”

A new gene, labelled ADRAM by the researchers, was found to not only act as a scaffold for molecules inside the cell, but also helped coordinate the formation of fear-extinction memory.

Until now, there have been no studies devoted to understanding these genes, or how they might influence brain function in the context of learning and memory.

Research suggests interrupting immune response improves multiple sclerosis outcomes

Multiple sclerosis is a chronic disease that damages neurons. A WVU doctoral student, Kelly Monaghan, is researching the role that a protein, STAT5, plays in the development of MS.
Credit: WVU Illustration/Aira Burkhart

A human immune system is a lot like the board game Mouse Trap: it’s a Rube Goldberg system of interacting parts. Only instead of a falling ball causing a tiny diver to leap into a tub—which, in turn, springs a trap on some plastic mice—proteins trigger other proteins to activate immune cells and direct them toward germs. But if those proteins mistakenly direct immune cells toward healthy tissue, autoimmune diseases like multiple sclerosis – which attacks neurons - can arise.

Kelly Monaghan
Footnote 1 Credit: WVU Photo/Tyler Mertins
A new study led by Kelly Monaghan—a researcher with the West Virginia University School of Medicine—suggests that part of the “Rube Goldberg” immune system shows promise as a potential target for MS therapies.

“Anytime you have any kind of central nervous system issues, you have to go through a series of steps to have cells get into the brain or spinal cord,” said Monaghan, a doctoral candidate in the Department of Microbiology, Immunology and Cell Biology. “Gaining a better understanding of those immune mechanisms associated with MS can help to inform novel therapies.”

Her findings appeared in the Proceedings of the National Academy of Science.

Her study—funded by the National Institutes of Health—focused on STAT5, one of the many proteins circulating in the body that can metaphorically turn genes on or off.

Nanoparticle-based COVID-19 vaccine could target future infectious diseases

SNAs are ball-like forms of DNA and RNA
arranged on the surface of a nanoparticle
Just one dose of a new nanoparticle-based COVID-19 vaccine was enough to produce an immune response in animals on track with vaccines currently in clinical use. And with minor changes, Northwestern University researchers hope the same vaccine platform could target other infectious diseases.

In a new study, 100% of mice who received the protein-based immunization survived when challenged with lethal doses of the SARS-CoV-2 virus, which causes COVID-19. None of the mice experienced lung damage due to SARS-CoV-2 exposure. All mice who did not receive this nanoparticle vaccine died in a 14-day trial.

The results, published this week in the Proceedings of the National Academy of Sciences, outline the structure-function relationships between the first spherical nucleic acid (SNA) vaccine developed to protect against viral infections.

“What makes this vaccine different than other vaccines is the approach we take to design them,” said Dr. Michelle Teplensky, co-first author of the paper. “Even as recently as a few years ago people focused on selecting the right target to train the immune system and the right stimulant to activate it, not on how those components were arranged structurally and presented to the body.”

Called SNAs, the nanoparticles that house the immune target are a form of globular DNA that can enter and stimulate immune cells with extreme efficiency. SNAs have been tested in more than 60 cell types. Researchers experimentally determined the ideal ratio between the SNA’s shell and core density that produces the most potent response.

SNA vaccines have been used to treat mice with triple negative breast cancer — and more vaccines for other cancers are in development.

A sulphurous end for the dinosaurs, according to new research

Artist's impression of dinosaur extinction
Credit: James McKay
Climate cooling associated with Sulphur gases directly contributed to the extinction of the dinosaurs, research carried out at the Universities of St Andrews and Bristol has found.

The gases were ejected into the Earth’s atmosphere after a six-mile-wide asteroid hit what is now the Yucatan Peninsula, around 66 million years ago.

The research, published today in PNAS (Proceedings of the National Academy of Sciences) in collaboration with Syracuse University (New York, US), and Texas A&M explored the consequences of the asteroid impact known as the Chicxulub impact.

The research team found that Sulphur gases circulated globally for years in the Earth’s atmosphere, cooling the climate and contributing to the mass extinction of life. This extinction event was catastrophic for dinosaurs and other life but also allowed for the diversification of mammals including primates.

Dr James Witts of the School of Earth Sciences at the University of Bristol said: “Our data provides the first direct evidence for the massive amounts of Sulphur released by the Chicxulub impact. It’s amazing to be able to see such rapid and catastrophic global change in the geological record.”

Dr Aubrey Zerkle of the School of Earth and Environmental Sciences at the University of St Andrews, explained: “One reason this particular impact was so devastating to life seems to be that it landed in a marine environment that was rich in Sulphur and other volatiles. The dinosaurs were just really unlucky!”

New study defines spread of SARS-CoV-2 in white-tailed deer

White-Tailed Deer
Credit: Heidi-Ann Fourkiller / SFLORG

North American white-tailed deer – shown in 2021 surveys of five states to have SARS-CoV-2 infection rates of up to 40% – shed and transmit the virus for up to five days once infected, according to a new study.

“It’s a relatively short window of time in which the infected animals are shedding and are able to transmit the virus,” said Dr. Diego Diel, associate professor in the Department of Population Medicine and Diagnostic Sciences and director of the Virology Laboratory at the College of Veterinary Medicine’s Animal Health Diagnostic Center. “However, the virus is very efficient at transmitting to white-tailed-deer entering contact with infected animals.”

The study, “From Deer-to-Deer: SARS-CoV-2 is Efficiently Transmitted and Presents Broad Tissue Tropism and Replication Sites in White-Tailed Deer,” which published online on March 21 in PLOS Pathogens, also identified that the virus develops and replicates in the deer’s respiratory tract, lymphoid tissues – including tonsils and several lymph nodes – and in central nervous system tissues.

“Virus replication in the upper respiratory tract – especially the nasal turbinates [nose structures] - is comparable with what is observed in humans and in other animals that are susceptible to the infection,” Diel said, “and I think that’s probably one of the reasons why the virus transmits so efficiently.” As with humans, the virus spreads between deer through nasal and oral secretions and aerosols.

Study ties present-day Native American tribe to ancestors in San Francisco Bay Area

U. of I. anthropology professor Ripan Malhi and his colleagues found genomic evidence linking present-day members of the Muwekma Ohlone Tribe in the San Francisco Bay Area with individuals who lived in the region several hundred to 2,000 years ago. 
Credit/Photo by L. Brian Stauffer

A genomic study of Native peoples in the San Francisco Bay Area finds that eight present-day members of the Muwekma Ohlone Tribe share ancestry with 12 individuals who lived in the region several hundred to 2,000 years ago.

Reported in the Proceedings of the National Academy of Sciences, the study challenges the notion that the Ohlone migrated to the area between A.D. 500-1,000, said Ripan Malhi, a professor of anthropology at the University of Illinois Urbana-Champaign, who led the research with Stanford University population genetics and society professor Noah Rosenberg in collaboration with a team of other scientists and members of the Muwekma Ohlone Tribe. The Muwekma Ohlone Tribal Council requested, contributed to and oversaw the study.

Previous studies of artifacts and language patterns suggested that the Ohlone were relative newcomers to the region. But the genomic research found a deep signal of continuity between the ancient population and the new one, the team reported.

Our sleep shows how risk-seeking we are

Test person sleeping in a familiar environment. The researchers derive the personal sleep profile from the measurement of the brain waves.
© Courtesy of Social Neuro Lab / UniBE

Each person has their own individual sleep profile which can be identified by electrical brain activity during sleep. Researchers at the University of Bern have now demonstrated that brain waves during periods of deep sleep in a specific area of the brain can be used to determine the extent of an individual’s propensity for risk during their everyday life.

Each day, we make countless decisions in which we take different risks – in road traffic, when buying shares or in our sexual behavior, for example. The propensity for risk varies from one individual to the next. Researchers led by Daria Knoch, Professor of Social Neuroscience at the University of Bern, have demonstrated that clues in the brain concerning an individual’s propensity for risk can be gathered as they sleep: “The fewer slow waves an individual has over their right prefrontal cortex during deep sleep, the greater their propensity for risk. Among other functions, this region of the brain is important to control one’s own impulses,” explains the neuroscientist. The results have recently been published in the journal “NeuroImage.”

Monday, March 21, 2022

How the Chagas pathogen changes the intestinal microbiota of predatory bugs

The predatory bug Rhodnius prolixus is one of the main vectors of Chagas disease in the north of South America and in Central America.
Photo: Dr Erwin Huebner, University of Manitoba, Winnipeg, Canada/ Wikimedia Commons
In Central and South America, predatory blood-sucking bugs transmit the causative agent of the widely prevalent Chagas disease. As the disease can induce severe symptoms and to date there is no vaccine against the Trypanosoma parasites, the main approach at present is to control the bug using insecticides. A German-Brazilian research team has now studied how trypanosomes change the bug's intestinal microbiota. The long-term goal: to change the bacterial community in the predatory bug's intestine in such a way that it can defend itself against the trypanosomes.

According to estimates by the World Health Organization (WHO), between six and seven million people worldwide, predominantly in Central and South America, are infected with the Trypanosoma cruzi species of trypanosome. This single-celled (protozoan) parasite causes Chagas disease (American trypanosomiasis), which in the acute phase is inconspicuous: only in every third case does the infected person develop any symptoms at all, which can then be unspecific, such as fever, hives and swollen lymph nodes. However, the parasites remain in the body, and many years later chronic Chagas disease can become life-threatening, with pathological enlargement of the heart and progressive paralysis of the gastrointestinal tract.

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