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Comment by Dr. Krishna Kumari Challa on June 14, 2023 at 10:25am

 How microplastics stick around in human airways

Research shows humans might inhale about 16.2 bits of microplastic every hour, which is equivalent to a credit card over an entire week. And these microplastics—tiny debris in the environment generated from the degradation of plastic products—usually contain toxic pollutants and chemicals.

Inhaled microplastics can pose serious health risks, so understanding how they travel in the respiratory system is essential for prevention and treatment of respiratory diseases.

Researchers  explored the movement of microplastics with different shapes (spherical, tetrahedral, and cylindrical) and sizes (1.6, 2.56, and 5.56 microns) and under slow and fast breathing conditions.

Microplastics tended to collect in hot spots in the nasal cavity and oropharynx, or back of the throat.

The complicated and highly asymmetric anatomical shape of the airway and complex flow behavior in the nasal cavity and oropharynx causes the microplastics to deviate from the flow pathline and deposit in those areas.

The flow speed, particle inertia, and asymmetric anatomy influence the overall deposition and increase the deposition concentration in nasal cavities and the oropharynx area.

Breathing conditions and microplastic size influenced the overall microplastic deposition rate in airways. An increased flow rate led to less deposition, and the largest (5.56 micron) microplastics were deposited in the airways more often than their smaller counterparts.

This study emphasizes the need for greater awareness of the presence and potential health impacts of microplastics in the air we breathe.

How microplastics are transported and deposited in realistic upper airways, Physics of Fluids (2023). DOI: 10.1063/5.0150703

Comment by Dr. Krishna Kumari Challa on June 14, 2023 at 9:49am

One consistent finding throughout the populations studied was that age was not the single determinant factor in a person's response to inflammatory stress. Some younger persons with poor immune resilience had the same signatures and immune health grades commonly seen in older persons. This finding suggests that the ability to restore and maintain immunocompetence at younger ages may be linked to life span. Another factor noted across the populations and species was that higher levels of optimal immune resilience were observed more often in females than males.

These assessments have utility for understanding who might be at greater risk for developing diseases that affect the immune system, how individuals are responding to treatment, and whether, as well as to what extent, they will recover.

Sunil Ahuja, Immune resilience despite inflammatory stress promotes longevity and favorable health outcomes including resistance to infection, Nature Communications (2023). DOI: 10.1038/s41467-023-38238-6. www.nature.com/articles/s41467-023-38238-6

Part 2

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

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