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Comment by Dr. Krishna Kumari Challa on March 1, 2024 at 9:54am

‘Epigenetic’ editing cuts cholesterol in mice

Changes to chemical tags on DNA in mice dial down the activity of a gene without cuts to the genome.

An alternative to genome editing can reduce the activity of a gene that affects cholesterol levels without changing the DNA sequence — and does so for an extended period, according to a study1 in mice.

Scientists achieved this effect by changing each animal’s ‘epigenome’, one feature of which is a collection of chemical tags that are bound to DNA and affect gene activity. After the treatment, activity of the targeted gene dropped and remained low for the 11 months over which the mice were studied.

https://www.nature.com/articles/d41586-024-00563-1?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on March 1, 2024 at 9:53am

How humans lost their tails
Researchers have shown that humans and other apes carry a DNA insertion in a gene called TBXT that other primates with tails, such as monkeys, don’t have. And mice carrying similar alterations to their genomes have short or absent tails. “They clearly show that this change contributes to tail loss. But it’s not the only one,” says human geneticist Malte Spielmann. Apes aren’t the only primates without tails, suggesting that the trait evolved multiple times. “Probably, there are multiple ways of losing a tail during development. Our ancestors chose this way,” says co-author Bo Xia.

https://www.nature.com/articles/d41586-024-00610-x?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on March 1, 2024 at 9:39am

Taking the motion sickness out of space travel

In lab experiments, aerospace engineers spin and rock human subjects--all in an effort to help prevent motion sickness when astronauts return to Earth and land in the choppy ocean.

Comment by Dr. Krishna Kumari Challa on March 1, 2024 at 9:29am

AI reveals prostate cancer is not just one disease

Artificial Intelligence has helped scientists reveal a new form of aggressive prostate cancer that could revolutionize how the disease is diagnosed and treated in the future.

The study published in Cell Genomics reveals that prostrate cancer, which affects one in eight men in their lifetime, includes two different subtypes termed evotypes.

The discovery was made by an international team led by the University of Oxford, and the University of Manchester, who applied AI on data from DNA to identify two different subtypes affecting the prostate.

The team hopes their findings could save thousands of lives in future and revolutionize how prostate cancer is diagnosed and treated. Ultimately, it could provide tailored treatments to each individual patient according to a genetic test which will also be delivered using AI.

This understanding is pivotal as it allows us to classify tumors based on how the cancer evolves rather than solely on individual gene mutations or expression patterns.

The researchers used AI to study changes in the DNA of prostate cancer samples (using whole genome sequencing) from 159 patients.

They identified two distinct cancer groups among these patients using an AI technique called neural networks. These two groups were confirmed by using two other mathematical approaches applied to different aspects of the data. This finding was validated in other independent datasets from Canada and Australia.

They went on to integrate all the information to generate an evolutionary tree showing how the two subtypes of prostate cancer develop, ultimately converging into two distinct disease types termed "evotypes."

Genomic evolution shapes prostate cancer disease type, Cell Genomics (2024). DOI: 10.1016/j.xgen.2024.100511. www.cell.com/cell-genomics/ful … 2666-979X(24)00038-7

Comment by Dr. Krishna Kumari Challa on February 28, 2024 at 9:52am

You may be breathing in more tiny nanoparticles from your gas stove than from car exhaust

A new study has found that cooking on your gas stove can emit more nano-sized particles into the air than vehicles that run on gas or diesel, possibly increasing your risk of developing asthma or other respiratory illnesses.

Combustion remains a source of air pollution across the world, both indoors and outdoors. Researchers found that cooking on your gas stove produces large amounts of small nanoparticles that get into your respiratory system and deposit efficiently.

Based on these findings, the researchers would encourage turning on a kitchen exhaust fan while cooking on a gas stove.

Recent studies have found that children who live in homes with gas stoves are more likely to develop asthma. But not much is known about how particles smaller than 3 nanometers, called nanocluster aerosol, grow and spread indoors because they're very difficult to measure. These super tiny nanoparticles are so small that you're not able to see them. They're not like dust particles that you would see floating in the air. After observing such high concentrations of nanocluster aerosol during gas cooking, we can't ignore these nano-sized particles anymore, say scientists. This would mean that adults and children could be breathing in 10 to 100 times more nanocluster aerosol from cooking on a gas stove indoors than they would from car exhaust while standing on a busy street.

Since most people don't turn on their exhaust fan while cooking, having kitchen hoods that activate automatically would be a logical solution.

 Brandon Boor et al, Dynamics of nanocluster aerosol in the indoor atmosphere during gas cooking, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae044. academic.oup.com/pnasnexus/art … /3/2/pgae044/7614671

Comment by Dr. Krishna Kumari Challa on February 28, 2024 at 9:45am

There are different types of optical tweezers. For example, free-space optical tweezers can manipulate an object in an open environment such as air or liquid without any physical barriers or structures guiding the light. But in this study, the researchers built nanotweezers embedded in an optofluidic device that integrates optical and fluidic technologies on a single chip.

The chip contains silicon-based photonic crystal cavities—the nanotweezers, which are essentially tiny traps that gently nudge the phages into position using a light-generated force field. The system allowed the researchers to precisely control single bacteria and single virions and acquire information about the trapped microorganisms in real time.

What sets this approach apart is that it can distinguish between different types of phages without using any chemical labels or surface bioreceptors, which can be time-consuming and sometimes ineffective. Instead, the nanotweezers distinguish between phages by reading the unique changes each particle causes in the light's properties. The label-free method can significantly accelerate the selection of therapeutic phages, promising faster turnaround for potential phage-based treatments.
The research also has implications beyond phage therapy. Being able to manipulate and study single virions in real time opens up new avenues in microbiological research, offering scientists a powerful tool for rapid testing and experimentation. This could lead to a deeper understanding of viruses and their interactions with hosts, which is invaluable in the ongoing battle against infectious diseases.

Nicolas Villa et al, Optical Trapping and Fast Discrimination of Label‐Free Bacteriophages at the Single Virion Level, Small (2024). DOI: 10.1002/smll.202308814

Part 2

Comment by Dr. Krishna Kumari Challa on February 28, 2024 at 9:44am

Nanotweezers manipulate bacteriophages with minimal optical power, a breakthrough for phage therapy

Scientists  have developed a game-changing technique that uses light to manipulate and identify individual bacteriophages without the need for chemical labels or bioreceptors, potentially accelerating and revolutionizing phage-based therapies that can treat antibiotic-resistant bacterial infections.

With antibiotic resistance looming as a formidable threat to our health, scientists are on a constant quest for alternative ways to treat bacterial infections. As more and more bacterial strains outsmart drugs we have been relying on for decades, a possible alternative solution may be found in bacteriophages, which are viruses that prey on bacteria.

Phage therapy, the use of bacteriophages to combat bacterial infections, is gaining attraction as a viable alternative to traditional antibiotics. But there is a catch: Finding the right phage for a given infection is like searching for a needle in a haystack, while current methods involve cumbersome culturing, time-consuming assays.

Now, scientists  have developed on-chip nanotweezers that can trap and manipulate individual bacteria and virions (the infectious form of a virus) using a minimal amount of optical power. The study is published in the journal Small.

The nanotweezers are a type of optical tweezers, scientific instruments that use a highly focused laser beam to hold and manipulate microscopic (e.g., virions) and even sub-microscopic objects like atoms in three dimensions. The light creates a gradient force that attracts the particles towards a high-intensity focal point, effectively holding them in place without physical contact.

Part 1

Comment by Dr. Krishna Kumari Challa on February 28, 2024 at 9:10am

Lake bottom testing shows plastics migrating down into sediment layers

A team of environmentalists, geographers and ecologists affiliated with several institutions in Europe has found that microplastics have migrated into multiple sediment layers in three lakes in Latvia. In their study, published in the journal Science Advances, the group drilled core samples from three lakes in Latvia and analyzed their contents for microplastics.

Research over the past few years has shown that microplastics have become pervasive around the planet, from soil where food is grown, to rivers, lakes and streams—and even the clouds. Prior research has also suggested that the Earth has entered a new geological age, moving from the Holocene Epoch to the Anthropocene, a change that most in the Earth science community believe began in the 1950s.

Most also agree that the transition is the result of human impact. And because plastics have been tied to so many of the changes that have occurred, some suggest using its presence as a barometer to measure the start of the Anthropocene. In this new study, the research team working in Latvia has found that doing so many not be feasible.

The work involved collecting core sediment samples from the bottom of three lakes in Latvia. Each of the samples was then analyzed to measure amounts of plastic. At the outset, the researchers assumed that sample portions preceding the creation and use of plastics would be zero. Unfortunately, that was not the case.

The researchers found plastics in sediment that had been deposited as far back as the early 1700s, a finding that indicates that plastics can migrate through sediment down to lower layers. This finding prevents the use of plastics as a barometer for the onset of the Anthropocene.

The researchers also note that because there are so many factors involved, including the type of soil that makes up sediment, material in the water and its temperature, and the many types of plastics found, studying their source would prove to be exceedingly challenging.

Inta Dimante-Deimantovica et al, Downward migrating microplastics in lake sediments are a tricky indicator for the onset of the Anthropocene, Science Advances (2024). DOI: 10.1126/sciadv.adi8136

Comment by Dr. Krishna Kumari Challa on February 27, 2024 at 11:38am

Microplastics Found in Every Human Placenta Tested, Study Finds

It's been over three years since scientists first found microplastics swimming in four different human placentas, and as it turns out, that was just the tip of the iceberg. A few years later, at the start of 2023, researchers announced they had found microscopic particles of plastic waste in no fewer than 17 different placentas. By the end of 2023, a local study in Hawai'i analyzed 30 placentas that were donated between 2006 and 2021 only to find plastic contamination had increased significantly over time. Using a new technique, researchers have now identified tiny particles and fibers of plastic less than a micron in size in the largest sample of placentas yet. In all 62 tissue samples studied, the team found microplastics of various concentrations in every single one. These concentrations ranged from 6.5 to 685 micrograms per gram of tissue, which is much higher than levels found in the human bloodstream. No one yet knows what this plastic pollution is doing – if anything – to the health of the fetus or the mother. While microplastics have been found in every major organ of the human body, including the brain, it's unknown if these pollutants are temporary visitors or permanent and accumulating threats to health. As environmental plastic pollution continues to worsen, contamination of the placenta is on track to only increase, as humans breathe in and ingest more plastic than ever before.

And dose makes the poison!

https://academic.oup.com/toxsci/advance-article-abstract/doi/10.109...

Comment by Dr. Krishna Kumari Challa on February 27, 2024 at 10:28am

Cosmic dust could have helped get life going on Earth

Life on our planet appeared early in Earth's history. Surprisingly early, since in its early youth our planet didn't have much of the chemical ingredients necessary for life to evolve. Since prebiotic chemicals such as sugars and amino acids are known to appear in asteroids and comets, one idea is that Earth was seeded with the building blocks of life by early cometary and asteroid impacts. While this likely played a role, a new study published in Nature Astronomy shows that cosmic dust also seeded young Earth, and it may have made all the difference.

Craig R. Walton et al, Cosmic dust fertilization of glacial prebiotic chemistry on early Earth, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02212-z

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