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Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 10:22am

What microplastics might be doing to our intestines

Plastics are among the most ubiquitous manmade materials—we wear them, build with them, play with them, ship goods in them, and then we throw them into the waste stream. Ultimately, they can break down into tiny particles that get into our food supply, and we end up eating them.

These particles can range from about the size of pollen (microplastics) down to a fraction of the size of a virus (nanoplastics), and they have penetrated water supplies, agricultural soil beds, and natural and domestic food chains.
Knowledge of the effects of ingesting microplastics and nanoplastics has been limited by their ubiquitous nature—making it difficult to find populations of unaffected individuals to act as control groups—and the lack of relevant laboratory models for studying the particles' effects on cells.

In a study published in Nanomedicine: Nanotechnology, Biology and Medicine, researchers  have found potential inflammatory effects of plastic particles using human intestinal organoids—small bundles of tissue made from a mix of human cells obtained from biopsies that mimic the complexity of an actual intestinal environment.

Notably, the researchers found that higher concentrations of plastic particles triggered the secretion of inflammatory molecules linked to human inflammatory bowel disease (IBD).

Earlier clinical studies have found plastics accumulated in different tissues of living organisms, including the digestive tract, blood, liver, pancreas, heart, and even the brain. The most likely first point of entry is through the intestine. Studies on rats and other animals have found that while microplastics and nanoplastics may accumulate in the intestine and other tissues, there are conflicting results on toxic effects or inflammation, which may depend on particle size, length of exposure, and pre-existing conditions. 

We know that particulate plastic is everywhere in the environment, and it has been found in human intestines and other tissues, like blood, and even in the brain and placenta.

Different cells were found to absorb different sizes of particles. Epithelial cells that normally line the inside of the intestine would absorb the tiniest nanoparticles, while microfold or "M" cells would absorb and transport larger microparticles into the intestinal tissue. The researchers also found that damage caused by plastic particles to the model intestinal lining occurred only when M cells were present and at higher concentrations of particles. Damage to the cell layer may imply the potential for generating intestinal lesions.

Part 1

Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 10:14am

Gout strongly associated with reduced gray matter and increased neurodegenerative disease

Researchers recently conducted a study  a study into the relationship between gout and neurodegenerative disease. In the paper, "Association of gout with brain reserve and vulnerability to neurodegenerative disease," published in Nature Communications, they find remarkable links between the common arthritis joint ailment and neurodegenerative disease.

The results from a combination of observational and genetic approaches indicate that gout patients have smaller global and regional brain volumes and markers of higher brain iron. Participants with gout also had higher incidences of all-cause dementia, Parkinson's disease, and probable essential tremor, particularly in the first three years after diagnosis.

The observations suggest that lower neuroanatomic resources among gout patients may explain their higher vulnerability to multiple neurodegenerative diseases. Genetic associations mostly mirrored observational ones. Both genetically predicted gout and serum urate were significantly associated with regional gray matter volumes.

Gout is the most common inflammatory arthritis affecting ~1% to 4% of the population. Insufficient kidney filtering or overproduction of uric acid can cause a build-up and the formation of tiny sharp crystals in and around joint tissues. The clinical syndrome of gout is characterized by acute joint pain and swelling resulting from urate crystals. The brain has not been previously thought to be affected.

These results support a strong correlation between gout and neurodegenerative disease. The authors suggest that patients with gout should be monitored for cognitive and motor symptoms of neurodegenerative disease, given their increased risk, especially in the early period after diagnosis.

Anya Topiwala et al, Association of gout with brain reserve and vulnerability to neurodegenerative disease, Nature Communications (2023). DOI: 10.1038/s41467-023-38602-6

Comment by Dr. Krishna Kumari Challa on June 12, 2023 at 10:49am

White Dwarf Star Enters Its Crystallization Era, Turning Into A 'Cosmic Diamond'

To us, stars may resemble cut jewels, glittering coldly against the velvet darkness of the night sky. And for some of them, that may actually be sort of true.

As a certain type of dead star cools, it gradually hardens and crystallizes. Astronomers have found one doing just that in our cosmic backyard, a white dwarf composed primarily of carbon and metallic oxygen just 104 light-years away, whose temperature-mass profile suggests that the center of the star is transforming into a dense, hard, 'cosmic diamond' made up of crystallized carbon and oxygen.

White dwarf stars are dim, but they still shine with residual heat. Over time, they cool, and are expected to evolve into something called a black dwarf stars when they lose all their heat and become a cold lump of crystallized carbon.

Calculations suggest that this process takes a very long time, about a quadrillion years (that's a million billion years); since the Universe is only about 13.8 billion years old, we don't expect to find one anytime soon.

What we can do is identify the signs of crystallization starting in the cores of the white dwarfs we see around us.

During crystallization, the carbon and oxygen atoms inside the white dwarf stop moving about freely and form bonds, arranging themselves into a crystal lattice. Energy is released during this process, which dissipates in the form of heat.

This produces a sort of plateau or slowing in the cooling of white dwarf stars, which can be observed in the color and brightness of the star, making it appear younger than it actually is.

https://arxiv.org/abs/2306.03140

The discovery is detailed in a paper accepted into the Monthly Notices of the Royal Astronomical Society and available on preprint website arXiv.

Comment by Dr. Krishna Kumari Challa on June 12, 2023 at 10:38am

Our own genetic instructions for survival can change, but it tends to happen slowly, with generational tweaking of DNA. Variations in the genetic code determine the ultimate shape and function of individual proteins that build our bodies, including the systems and structural supports inside our brain.

DNA doesn't make the proteins directly, though. Those chemically encoded instructions remain in the nucleus of your cells, issuing templates through an intermediate molecule called messenger RNA (or mRNA), which travels from the nucleus into the surrounding goo to feed into tiny protein-building machines.

In most organisms, this is pretty straightforward; once the template is issued, no more change occurs to the RNA. In cephalopods, however, things are a little different.

In 2015, scientists found that squids, cuttlefish, and octopuses can tweak the RNA after it has left the nucleus, editing on the fly, allowing for a rapid physiological response to … what? Some scientists thought it might be the reason cephalopods are so strangely, fascinatingly smart, but the reason for it has eluded us, and baffled scientists.

Adapting to temporary environmental changes seemed like a plausible explanation. Marine organisms are subjected to a wide range of temperatures, and octopuses lack the ability to actively thermoregulate. RNA editing would offer the ability to change, and change again as conditions dictate, without the long-term implementation and relative permanence of DNA editing.

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These findings suggest that at least one function of cephalopod RNA editing is a rapid response to conditions that might be dangerous to the animals otherwise. There are also other environmental variables that could invoke a response. These include low oxygen, pollution, and changing social conditions.

The researchers suspect that RNA editing is a fairly widespread strategy among octopuses and squids to stay alive as their environment changes, and plan to investigate how it is used in greater detail.

https://www.cell.com/cell/fulltext/S0092-8674(23)00523-8

Part 2

Comment by Dr. Krishna Kumari Challa on June 12, 2023 at 10:36am

Octopuses Can Rewire Their 'Brains' by Editing Their Own RNA on The Fly

Octopuses have found an incredible way to protect the more delicate features of their nervous system against radically changing temperatures.

When conditions fluctuate, they can rapidly recode key proteins in their nerve cells, ensuring critical neurological activities remain functional when temperatures drop dramatically.

How do they do it? By deploying a rare superpower – editing their RNA on the fly, an ability found in some species of octopuses, squids and cuttlefish.

It's an unusual strategy, but it appears to be an effective one, and scientists think that it may be widely adopted throughout the world of cephalopods.

We generally think that our genetic information is fixed, but the environment can influence how you encode proteins, and in cephalopods this happens on a massive scale.

RNA recoding gives organisms the option to express a diverse quiver of proteins when and where they choose. In cephalopods, most of the recoding is for proteins that are really important for nervous system function, so the natural question is, are they using this to acclimate to changes in their physical environment?"

Part 1

Comment by Dr. Krishna Kumari Challa on June 12, 2023 at 10:30am

Why you can’t eat or drink before a general anaesthetic

When you have a general anaesthetic, you will usually be asked not to have anything to eat or drink for a period of time before. Although you might get annoyed, this is for your won safety. 

When the general anaesthetic is used, your body’s reflexes are temporarily stopped. If your stomach has any food and drink in it, there’s a risk of vomiting or bringing up food into your throat. If this happens, the food could get into your lungs and affect your breathing, as well as causing damage. Inhaling vomited stomach contents into your lungs is called ‘aspiration’, and it can lead to a dangerous infection.

The amount of time you have to go without food or drink before you have your operation will depend on the type of operation you’re having. However, it is usually at least six hours for food, and two hours for fluids. You’ll be told how long you must not eat or drink before your operation.

Unfortunately, even chewing gum – including nicotine gum – should be avoided during this fasting period, and soups and sweets should also not be consumed. You may also be advised to avoid certain types of fluids, such as milk, or tea and coffee with milk added to them. Clear fluids, such as water, are usually allowed until two hours before.

While it might feel annoying to avoid food, you must follow the guidelines. If you eat or drink before your surgery, your operation can be postponed or even cancelled because of the risks involved.

Comment by Dr. Krishna Kumari Challa on June 12, 2023 at 9:40am

Researchers discover that COVID-19 can cause brain cells to fuse

Researchers have discovered viruses such as SARS-CoV-2 can cause brain cells to fuse, initiating malfunctions that lead to chronic neurological symptoms. They have explored how viruses alter the function of the nervous system. Their research is published in Science Advances.

SARS-CoV-2, the virus that causes COVID-19, has been detected in the brains of people with "long COVID" months after their initial infection.

It's discovered now that COVID-19 causes neurons to undergo a cell fusion process, which has not been seen before.

Once fusion takes place, each switch either turns on both the kitchen and bathroom lights at the same time, or neither of them.  It's bad news for the two independent circuits.

The discovery offers a potential explanation for persistent neurological effects after a viral infection. In the current understanding of what happens when a virus enters the brain, there are two outcomes—either cell death or inflammation. But this new work has shown a third possible outcome, which is neuronal fusion.

Numerous viruses cause cell fusion in other tissues, but also infect the nervous system and could be causing the same problem there.

These viruses include HIV, rabies, Japanese encephalitis, measles, herpes simplex virus and Zika virus. This  research reveals a new mechanism for the neurological events that happen during a viral infection. This is potentially a major cause of neurological diseases and clinical symptoms that is still unexplored.

Ramón Martínez-Mármol et al, SARS-CoV-2 infection and viral fusogens cause neuronal and glial fusion that compromises neuronal activity., Science Advances (2023). DOI: 10.1126/sciadv.adg2248. www.science.org/doi/10.1126/sciadv.adg2248

Comment by Dr. Krishna Kumari Challa on June 11, 2023 at 1:05pm

 Amorphous Ice

Comment by Dr. Krishna Kumari Challa on June 10, 2023 at 1:13pm

Millions wasted on reformatting papers

Scientists are spending millions of dollars’ worth of time reformatting rejected papers for submission to alternative journals. An analysis shows that, in 2021, the global price tag on all of tha... — just for biomedical journals. If current journal practices don’t change, the authors estimate that reformatting could cost about $2.5 billion between 2022 and 2030. Suggested remedies include universal journal guidelines, free-format submissions or a ‘golden middle’ solution that allows researchers to submit manuscripts that abide by minimal structural requirements, such as total word count. “The current system is not sustainable,” says study co-author Tibor Varga.

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Why didn't the Big Bang collapse in a giant black hole?

Despite the enormous densities, the early universe didn't collapse into a black hole because, simply put, there was nothing to collapse into.

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Limiting global warming to 2C is not enough—why the world must keep...

The Paris Climate agreement represented a historic step towards a safer future for humanity on Earth when it was adopted in 2015. The agreement strove to keep global heating below 2℃ above pre-industrial levels with the aim of limiting the increase to 1.5℃ if possible. It was signed by 196 parties around the world, representing the overwhelming majority of humanity.

Comment by Dr. Krishna Kumari Challa on June 10, 2023 at 10:52am

What Dreams May Mean
Dreams can be bizarre and disturbing, and even sometimes frightening. Do some betray a pathology? Dreams alone are not enough to diagnose a mental illness. But some characteristics of a dream may hint at disorders: for example, the frequency of nightmares is generally higher in people with a mental disorder, whether depression, anxiety or post-traumatic stress disorder (they’re particularly indicative of a person’s risk for suicide).

Why this is cool: Dreams may serve to integrate memories and lessen negative emotions around difficult life experiences; in fact, people tend to wake up happier than when they went to sleep (what I’m hearing: more naps, because SCIENCE). Those systems can get derailed in people with depression or PTSD.

What the experts say: Dreams can be useful in diagnosing some brain disorders, like differentiating between Alzheimer's and Lewy body dementia. Both involve cognitive loss, but the latter is accompanied by REM sleep behavior disorder, where the dreamer tries to physically act out what’s happening in their dream.

https://www.scientificamerican.com/article/how-dreams-reveal-brain-...

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