Comment

Comment by Dr. Krishna Kumari Challa on June 14, 2023 at 9:47am

People who preserve 'immune resilience' live longer and resist infections, study finds

Researchers have revealed that the capacity to resist or recover from infections and other sources of inflammatory stress—called "immune resilience"—differs widely among individuals. The researchers developed a unique set of metrics to quantify the level of immune resilience. This will aid in decisions for health care and help researchers understand differences in life span and health outcomes in persons of similar ages. 

Although age plays an important role in the body's response to infectious and other inflammatory stressors, some persons preserve and/or restore optimal immune resilience regardless of age.

Immune resilience is the capacity to maintain good immune function, called immunocompetence, and minimize inflammation while experiencing inflammatory stressors. 

Researchers found that during aging and when experiencing inflammatory stress, some persons resist degradation of immune resilience.

individuals with optimal levels of immune resilience were more likely to:

• Live longer.
• Resist HIV and influenza infections.
• Resist AIDS.
• Resist recurrence of skin cancer after kidney transplant.
• Survive COVID-19 infection.
• Survive sepsis.

Part 1

Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 12:13pm

Using Nanoparticles to Combat Antibiotic Resistance Bacteria

Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 12:11pm

New study reveals how blood triggers brain disease

 In patients with neurological diseases like Alzheimer's disease and multiple sclerosis, immune cells in the brain known as microglia that normally fulfill beneficial functions become harmful to neurons, leading to cognitive dysfunction and motor impairment. These harmful immune cells may also contribute to age-related cognitive decline in people without dementia.

For some time, scientists have been trying to better understand the triggers responsible for turning good microglia bad, and their exact contribution during disease. If they could identify what makes microglia toxic, they could find new ways to treat neurological diseases.

Now, researchers  showed that exposure to blood leaking into the brain turns on harmful genes in microglia, transforming them into toxic cells that can destroy neurons.

The scientists discovered that a blood protein called fibrin—which normally aids blood clotting—is responsible for turning on the detrimental genes in microglia, both in Alzheimer's disease and multiple sclerosis. The findings, published in the journal Nature Immunology, suggest that counteracting the blood toxicity caused by fibrin can protect the brain from harmful inflammation and loss of neurons in neurological diseases.

Individuals with neurological diseases like Alzheimer's disease and multiple sclerosis have abnormalities within the vast network of blood vessels in their brain, which allow blood proteins to seep into brain areas responsible for cognitive and motor functions. Blood leaks in the brain occur early and correlate with worse prognosis in many of these diseases.

In the new study, the researchers found that different blood proteins activate distinct molecular processes in microglia. What's more, they identified that fibrin is responsible for driving unique gene and protein activities that make microglia toxic to neurons. The other blood proteins tested were not mainly responsible for these toxic effects.

https://www.nature.com/articles/s41590-023-01522-0

Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 10:33am

One unproven theory is that day length might have stalled at a constant value in Earth's distant past. In addition to tides in the ocean related to the pull of the moon, Earth also has solar tides related to the atmosphere heating up during daytime.

Solar atmospheric tides are not as strong as lunar oceanic tides, but this would not always have been the case. When Earth was rotating faster in the past, the tug of the moon would have been much weaker. Unlike the pull of the moon, the sun's tide instead pushes Earth. So while the moon slows Earth's rotation down, the sun speeds it up.

Because of this, if in the past these two opposite forces were to have become been equal to each other, such a tidal resonance would have caused Earth's day length to stop changing and to have remained constant for some time.

And that's exactly what the new data compilation showed.

Earth's day length appears to have stopped its long-term increase and flatlined at about 19 hours roughly between two to one billion years ago.

The timing of the stalling intriguingly lies between the two largest rises in oxygen.

The new study thus supports the idea that Earth's rise to modern oxygen levels had to wait for longer days for photosynthetic bacteria to generate more oxygen each day.

Mitchell, R.N. et al, Mid-Proterozoic day length stalled by tidal resonance, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01202-6. www.nature.com/articles/s41561-023-01202-6

part 2

Comment by Dr. Krishna Kumari Challa on June 13, 2023 at 10:31am

For a billion years of Earth's history our days were only 19 hours long, finds new study

Although we take the 24-hour day for granted, in Earth's deep past, days were even shorter.

Day length was shorter because the moon was closer. Over time, the moon has stolen Earth's rotational energy to boost it into a higher orbit farther from Earth.

Most models of Earth's rotation predict that day length was consistently shorter and shorter going back in time.

How do researchers measure ancient day length? In past decades, geologists used records from special sedimentary rocks preserving very fine-scale layering in tidal mud flats. Count the number of sedimentary layers per month caused by tidal fluctuations and you know the number of hours in an ancient day.

But such tidal records are rare, and those preserved are often disputed. Fortunately, there's another means of estimating day length.

Cyclostratigraphy is a geologic method that uses rhythmic sedimentary layering to detect astronomical "Milankovitch" cycles that reflect how changes in Earth's orbit and rotation affect climate. Two Milankovitch cycles, precession and obliquity, are related to the wobble and tilt of Earth's rotation axis in space. The faster rotation of early Earth can therefore be detected in shorter precession and obliquity cycles in the past.

Researchers took advantage of a recent proliferation of Milankovitch records, with over half of the data for ancient times generated in the past seven years.

Part 1

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

Notably, the researchers also observed that higher concentrations of plastic nanoparticles triggered the organoid layer to release inflammatory cytokines—molecules that are a part of the normal immune response, but may relate to diseases including Inflammatory Bowel Disease (IBD) when they are set off balance. This effect was also dependent on the presence of M cells, which suggests those cells play a critical role in mediating potential damage to the intestine by plastic microparticles. More research will have to be done to clarify the impact of concentration, chemistry and surface features of plastic  particles on M cell functions.

 Ying Chen et al, Biological effects of polystyrene micro- and nano-plastics on human intestinal organoid-derived epithelial tissue models without and with M cells, Nanomedicine: Nanotechnology, Biology and Medicine (2023). DOI: 10.1016/j.nano.2023.102680

Part 2

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.

--

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

• ‹ Previous
• 1
• …
• 133
• 134
• 135
• 136
• 137
• …
• 846
• Next ›
• Page