Biology & Medicine News and Discussions

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Scientists find microplastics in blood for first time

Microplastics had already been spotted in oceans, air and food—now researchers have found it in human blood.

Scientists have discovered microplastics in human blood for the first time, warning that the ubiquitous particles could also be making their way into organs.

The tiny pieces of mostly invisible plastic have already been found almost everywhere else on Earth, from the deepest oceans to the highest mountains as well as in the air, soil and food chain.

A Dutch study published in the Environment International journal on Thursday examined blood samples from 22 anonymous, healthy volunteers and found microplastics in nearly 80 percent of them.

Half of the blood samples showed traces of PET plastic, widely used to make drink bottles, while more than a third had polystyrene, used for disposable food containers and many other products.

https://phys.org/news/2022-03-scientist ... blood.html

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Medicines 3D-printed in seven seconds
https://phys.org/news/2022-03-medicines ... conds.html
by University College London

Medicines can be printed in seven seconds in a new 3D-printing technique that could enable rapid on-site production of medicines, reports a UCL-led research team.

The findings published in the journal, Additive Manufacturing, improve the prospects of how 3D printers could be integrated into fast-paced clinical settings for on-demand production of personalized medicines.

For the current study, the researchers loaded printlets (printed tables) with paracetamol, which is one of many medicines that can be produced with a 3D printer.

One of the leading techniques for 3D printing is vat photopolymerisation, which affords the highest resolution for complexity at microscales, and also suits many medications as it does not require high heat. For printing medicines, the technique uses a resin formulation, constituting the required drug dissolved in a solution of a photoreactive chemical, activated by light to solidify the resin into a printed tablet.

But vat polymerisation has been hampered by slow printing speeds, due to its layer-by-layer approach.

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New method for generating potent, specific binding proteins for new drugs

by Ian Haydon, University of Washington School of Medicine
https://phys.org/news/2022-03-method-po ... drugs.html

A team of scientists has created a powerful new method for generating protein drugs. Using computers, they designed molecules that can target important proteins in the body, such as the insulin receptor, as well as vulnerable proteins on the surface of viruses. This solves a long-standing challenge in drug development and may lead to new treatments for cancer, diabetes, infection, inflammation, and beyond.

The research, appearing today in the journal Nature, was led by scientists in the laboratory of David Baker, professor of biochemistry at the University of Washington School of Medicine and a recipient of the 2021 Breakthrough Prize in Life Sciences.

"The ability to generate new proteins that bind tightly and specifically to any molecular target that you want is a paradigm shift in drug development and molecular biology more broadly," said Baker.

Antibodies are today's most common protein-based drugs. They typically function by binding to a specific molecular target, which then becomes either activated or deactivated. Antibodies can treat a wide range of health disorders, including COVID-19 and cancer, but generating new ones is challenging. Antibodies can also be costly to manufacture.

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Unprecedented videos show RNA switching 'on' and 'off'
https://phys.org/news/2022-03-unprecede ... s-rna.html
by Amanda Morris, Northwestern University

Similar to a light switch, RNA switches (called riboswitches) determine which genes turn "on" and "off." Although this may seem like a simple process, the inner workings of these switches have confounded biologists for decades.

Now researchers led by Northwestern University and the University at Albany discovered one part of RNA smoothly invades and displaces another part of the same RNA, enabling the structure to rapidly and dramatically change shape. Called "strand displacement," this mechanism appears to switch genetic expression from "on" to "off."

Using a simulation they launched last year, the researchers made this discovery by watching a slow-motion simulation of a riboswitch up close and in action. Affectionately called R2D2 (short for "reconstructing RNA dynamics from data"), the new simulation models RNA in three dimensions as it binds to a compound, communicates along its length and folds to turn a gene "on" or "off."

The findings could have potential implications for engineering new RNA-based diagnostics and for designing successful drugs to target RNA to treat illness and disease.

The research is described in a new paper published today (March 28) in the journal Nucleic Acids Research (NAR), which has designated the study as a "Breakthrough Article." NAR reserves "Breakthrough Article" status for the most high-impact studies answering long-standing questions in nucleic acids research.

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New method for making tissue transparent could speed the study of many diseases
https://phys.org/news/2022-03-method-ti ... eases.html
by The Scripps Research Institute

Scientists at Scripps Research have unveiled a new tissue-clearing method for rendering large biological samples transparent. The method makes it easier than ever for scientists to visualize and study healthy and disease-related biological processes occurring across multiple organ systems.

Described in a paper in Nature Methods on March 28, 2022, and dubbed HYBRiD, the new method combines elements of the two main prior approaches to tissue-clearing technology, and should be more practical and scalable than either for large-sample applications.

"This is a simple and universal tissue-clearing technique for studies of large body parts or even entire animals," says study senior author Li Ye, Ph.D., assistant professor of neuroscience at Scripps Research.

Tissue-clearing involves the use of solvents to remove molecules that make tissue opaque (such as fat), rendering the tissue optically transparent—while keeping most proteins and structures in place. Scientists commonly use genetically encoded or antibody-linked fluorescent beacons to mark active genes or other molecules of interest in a lab animal, and tissue-clearing in principle allows these beacons to be imaged all at once across the entire animal.

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Researchers identify a potential window for treating ALS
https://medicalxpress.com/news/2022-03- ... w-als.html
by Johns Hopkins University School of Medicine

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that affects as many as 30,000 people in the United States, with 5,000 new cases diagnosed each year. It weakens muscles over time, impacting physical function and ultimately leading to death. There is no single cause for the disease and no known cure. However, Johns Hopkins Medicine researchers have found a possible window of opportunity during ALS treatment to target astrocyte abnormalities—a subtype of cells in the central nervous system that provide a structure to metabolically support neurons and fine-tune neuron network signaling.

The research team believes that astrocytes are actively involved in the death of motor neurons, which are cells in the brain and spinal cord that allow people to move, speak, swallow and breathe by sending commands from the brain to the muscles that carry out these functions.

"We think this is particularly important because the astrocyte dysfunction is active after symptom onset in patients with ALS," says Nicholas Maragakis, M.D., professor of neurology at the Johns Hopkins University School of Medicine and medical director of the Johns Hopkins ALS clinical trials unit. "This finding may enable us to target abnormalities in astrocytes for ALS treatment."

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Study shows that RNA can be targeted by small molecule drugs, creating new possibilities for disease treatment
https://phys.org/news/2022-03-rna-small ... ities.html
by Massachusetts General Hospital

RNA (ribonucleic acid) plays many roles in human health, and now a study in the journal Nature offers powerful evidence that RNA could also be a viable target for drug development. This work, led by researchers at Massachusetts General Hospital (MGH), suggests that a new class of biological factors numbering in the thousands can be targeted and thereby heralds a new era in drug development.

Nearly all drugs currently available target one of approximately 700 disease-related proteins among the roughly 20,000 human proteins identified by the Human Genome Project. However, in recent years there has been growing interest in expanding the list of "druggable" targets to include RNA. In cells, DNA (deoxyribonucleic acid) carries the genetic code for forming proteins. A segment of DNA is copied, or transcribed, into a "coding" RNA, which is in turn translated into protein. However, the vast majority of RNA in the human genome—98 percent—is "noncoding."

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The human genome is, at long last, complete
https://phys.org/news/2022-03-human-genome.html
by Rockefeller University

When scientists declared the Human Genome Project complete two decades ago, their announcement was a tad premature. A milestone achievement had certainly been reached, with researchers around the world gaining access to the DNA sequence of most protein-coding genes in the human genome. But even after 20 years of upgrades, eight percent of our genome still remained unsequenced and unstudied. Derided by some as "junk DNA" with no clear function, roughly 151 million base pairs of sequence data scattered throughout the genome were still a black box.

Now, a large international team led by Adam Phillippy at National Institutes of Health has revealed the final eight percent of the human genome in a paper published in Science. These long–missing pieces of our genome contain more than mere junk. Within the new data are mysterious pockets of noncoding DNA that do not make protein, but still play crucial roles in many cellular functions and may lie at the heart of conditions in which cell division runs amok, such as cancer.

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Genetic study of bacteria in livestock in China shows growing resistance to antibiotics
https://phys.org/news/2022-04-genetic-b ... tance.html
by Bob Yirka , Phys.org

An international team of researchers has found via genetic study of bacteria in livestock that there is a growing resistance to antibiotics used in China. In their paper published in the journal Nature Food, the group describes their whole-genome analysis of Escherichia coli samples collected from a large number of pigs, chickens, cattle and sheep raised in China between the years 1970 and 2019. They looked for genes that confer resistance to several commonly used antibiotics. They also explain why they believe their findings show China and other countries need to find new ways to battle bacterial infections in both humans and animals. Claire Heffernan, with the London International Development Centre, published a News & Views piece in the same journal issue outlining the history of antibiotics use in agriculture and the work done by the team in this new effort.