Comment

Comment by Dr. Krishna Kumari Challa 6 hours ago

Based on previous work by other teams, the researchers selected a few candidate enzymes made by the gut bacterium Akkermansia muciniphila and treated red blood cells – from multiple donors and various A and B subtypes – with them.

Importantly, for potential clinical use, the enzymes were incubated with high concentrations of red blood cells, at room temperature and for only 30 minutes – improving on the longer processing and less efficient conditions of previous candidates.

"These mild conditions without additives (for example, dextran) together with excellent enzyme efficacies are important feasibility parameters in clinical applications.
Crucially, the chosen enzymes also removed all four known extensions of group A and B antigens from red blood cells, in addition to the shorter, canonical A and B antigens of other blood subtypes.

Removing the long, sugary extensions reduced the incompatibility of treated B-type cells with plasma samples to less than 9 percent, and made reactions less severe where they did happen.

More work is required to understand why a small fraction of apparently sugarless red blood cells still cross-react with group O plasmas, and to improve the conversion of group A blood cells.

However, in finding enzymes that remove a greater variety of A and B antigens, the researchers say their study uncovers "a missing link" in the production of universal blood for transfusion and potentially organs for transplantation.

In 2022, researchers used a similar strategy (with different enzymes) to convert donated lungs from group A blood type to the universal type O under lab conditions. This new work might improve those efforts enough to satisfy the safety standards required for human transplant trials.
Lab-grown red blood cells are also in human trials to test whether they last longer than donated blood. If so, that could reduce the demand on blood supplies and also help patients requiring repeat transfusions avoid complications.

https://www.nature.com/articles/s41564-024-01663-4

Part 3

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Comment by Dr. Krishna Kumari Challa 6 hours ago

What's tricky is that there are now, as of 2022, more than 40 blood group systems beyond the ABO system and rhesus factor most are familiar with.

Even within the A and B blood groups, there are subtypes, with varying lengths and densities of the signature molecules protruding from the red cells' membranes.
Scientists recently reported the discovery of remarkably efficient enzymes, not only against A and B antigens but also against their extensions.

published paper

Part 2

Comment by Dr. Krishna Kumari Challa 6 hours ago

Enzymes Discovered in Gut Bacteria Can Change a Donor's Blood Groups

When a life hangs in the balance, blood transfusions can help sustain a patient – but only if the donor's blood type is a match.
A new discovery by researchers from Denmark and Sweden could help in those emergency situations, while also easing global shortages in blood supplies.
The team identified a mixture of enzymes made by a species of bacteria found in our guts that can, in lab studies, transform red blood cells into the universal type O with "remarkably high efficiencies" – improving on an idea hatched 40 years ago.

Like virtually all cells in the human body, red blood cells are covered in a fuzz of unique sugary structures. These vary from person to person, with some sporting type A structures and others type B. Some have both A and B, and others have neither, which is designated O.

Immune systems that have never seen types A or B will attack and destroy these cells on sight if they receive them in a transfusion, whereas type O blood is far more widely accepted for most recipients.

Because of this versatility, type O blood stocks are often used up, especially in medical emergencies where doctors must act quickly without knowing a patient's blood type.
Converting red blood cells into the universal type O is not a new idea. The technique was pioneered back in 1982, when scientists discovered an enzyme extracted from coffee beans that could strip type B cells of their surface sugars.

But that enzyme reaction was very inefficient, making large-scale use impractical, and despite early promise in clinical trials, safety concerns were raised. For unknown reasons, donor blood was sometimes still incompatible in recipients despite donor cells being stripped of nearly all their antigens.

So scientists went back to the drawing board, discovering other enzymes in collections of gut bacteria as recently as 2019.
Part 1

Comment by Dr. Krishna Kumari Challa 7 hours ago

**More than half of cats on farm died after drinking milk from cows infected with bird flu**
In yet another sign that bird flu is spreading widely among mammals, a new report finds more than half of cats at the first Texas dairy farm to have cows test positive for bird flu this spring died after drinking raw milk.

Published this week in the Emerging Infectious Diseases journal, the report details the early stages of the investigation into the spread of bird flu among the country's dairy farms.

Cats at the Texas farm had been fed raw milk from cows that turned out to be infected with avian influenza, also known as H5N1. A day after the farm noticed cows were getting sick, the cats started getting sick. In the end, more than half of the cats perished.
"The cats were found dead with no apparent signs of injury and were from a resident population of [approximately] 24 domestic cats that had been fed milk from sick cows," the scientists wrote in their report.

Tests of the samples collected from the brains and lungs of dead cats yielded results suggesting "high amounts of virus," and autopsies revealed "microscopic lesions consistent with severe systemic virus infection," in the eyes and brain, they said.
And some human beings too got infected with this bird flu virus.

In late March 2024, a human case of influenza A(H5N1) virus infection was identified after exposure to dairy cattle presumably infected with bird flu. Some bird flu infections of people have been identified in which the source of infection was unknown.
Source: The U.S. Centers for Disease Control and Prevention

https://www.cdc.gov/flu/avianflu/avian-in-humans.htm

Comment by Dr. Krishna Kumari Challa 7 hours ago

Tire toxicity faces fresh scrutiny after fish fatalities

For decades, concerns about automobile pollution have focused on what comes out of the tailpipe. Now, researchers and regulators say, we need to pay more attention to toxic emissions from tires as vehicles roll down the road.

At the top of the list of worries is a chemical called 6PPD, which is added to rubber tires to help them last longer. When tires wear on pavement, 6PPD is released. It reacts with ozone to become a different chemical, 6PPD-q, which can be extremely toxic—so much so that it has been linked to repeated fish kills in the US.

The trouble with tires doesn't stop there. Tires are made primarily of natural rubber and synthetic rubber, but they contain hundreds of other ingredients, often including steel and heavy metals such as copper, lead, cadmium, and zinc.

As car tires wear, the rubber disappears in particles, both bits that can be seen with the naked eye and microparticles. Testing by a British company, Emissions Analytics, found that a car's tires emit 1 trillion ultrafine particles per kilometer driven—from 5 to 9 pounds of rubber per internal combustion car per year.

And what's in those particles is a mystery, because tire ingredients are proprietary. You've got a chemical cocktail in these tires that no one really understands and is kept highly confidential by the tire manufacturers.

Regulators have only begun to address the toxic tire problem, though there has been some action on 6PPD.

Native American tribes have petitioned the Environmental Protection Agency to prohibit the chemical. The EPA said it is considering new rules governing the chemical. "We could not sit idle while 6PPD kills the fish that sustain us", they say.

But, tragically,  today there is no alternative to 6PPD.

One outstanding research question is whether 6PPD-q affects people, and what health problems, if any, it could cause. A study published in Environmental Science & Technology Letters found high levels of the chemical in urine samples from a region of South China, with levels highest in pregnant women.

The discovery of 6PPD-q, Molden said, has sparked fresh interest in the health and environmental impacts of tires.

Source: Environmental Science & Technology Letters

Comment by Dr. Krishna Kumari Challa 8 hours ago

Plastic particle air pollution is now pervasive and inhalation ranks as the second most likely pathway for human exposure.
The primary types are intentionally manufactured, including a wide array of cosmetics and personal care products such as toothpaste.

The secondary ones are fragments derived from the degradation of larger plastic products, such as water bottles, food containers and clothes.
Extensive investigations have identified synthetic textiles as a principal source of indoor airborne plastic particles, while the outdoor environment presents a multitude of sources encompassing contaminated aerosols from the ocean to particles originating from wastewater treatment.
Researchers' modelling found that breathing rate along with particle size and shape determined where in the respiratory system plastic particles would be deposited.

Faster breathing rates led to heightened deposition in the upper respiratory tract, particularly for larger microplastics, whereas slower breathing facilitated deeper penetration and deposition of smaller nanoplastic particles.
Particle shape was another factor, with non-spherical microplastic particles showing a propensity for deeper lung penetration compared to spherical microplastics and nanoplastics, potentially leading to different health outcomes.

These findings highlight the imperative consideration of breathing rates and particle sizes in health risk assessments associated with respiratory exposure to nano and microplastic particles.

Xinlei Huang et al, Transport and deposition of microplastics and nanoplastics in the human respiratory tract, Environmental Advances (2024). DOI: 10.1016/j.envadv.2024.100525

Part 2

Comment by Dr. Krishna Kumari Challa 8 hours ago

The journey of inhaled plastic particle pollution

With recent studies having established the presence of nano and microplastic particles in the respiratory systems of both human and bird populations, a new study has modeled what happens when people breathe in different kinds of plastic particles and where they end up.

Researchers used computational fluid-particle dynamics (CFPD) to study the transfer and deposition of nano and microplastic particles of different sizes and shapes depending on the rate of breathing.

The results of the modeling, published in the journal Environmental Advances, have pinpointed hotspots in the human respiratory system where plastic particles can accumulate, from the nasal cavity and larynx and into the lungs. The paper based on these results is titled, "Transport and deposition of microplastics and nanoplastics in the human respiratory tract."

Evidence 's mounting on the significant impact of nano and microplastics on respiratory health and the UTS study would provide essential insights for the development of targeted strategies to mitigate potential risks and ensure effective health interventions.
Experimental evidence has strongly suggested that these plastic particles amplify human susceptibility to a spectrum of lung disorders, including chronic obstructive pulmonary disease, fibrosis, dyspnea (shortness of breath), asthma, and the formation of what are called frosted glass nodules.
Part 1

Comment by Dr. Krishna Kumari Challa 8 hours ago

The scientists looked for connections the brain might have with inflammation and innate immunity, the defense system shared by all animals and the most ancient component of the immune system. Whereas the adaptive immune system remembers previous encounters with intruders to help it resist them if they invade again, the innate immune system attacks anything with common traits of germs. The relative simplicity of innate immunity lets it respond to new insults more quickly than adaptive immunity.

Prior studies in humans revealed that electrically stimulating the vagus nerve—a bundle of thousands of nerve fibers linking the brain and the body's internal organs—could reduce the response linked to a specific inflammatory molecule.
However, much remained unknown about the nature of this body-brain system: for instance, the generality of the brain's modulation of immunity and the inflammatory response, the selective lines of communication between the body and the brain, the logic of the underlying neural circuit, and the identity of the vagal and brain components that monitor and regulate inflammation.
Researchers turned to a bacterial compound that sets off innate immune responses. The scientists found that giving this molecule to mice activated the caudal nucleus of the solitary tract, or cNST, which is tucked inside the brainstem. The cNST plays a major role in the body-brain axis and is the primary target of the vagus nerve.
The scientists showed that chemically suppressing the cNST resulted in an out-of-control inflammatory response to the immune insult: levels of pro-inflammatory molecules released by the immune system were more than three times higher than usual, and levels of anti-inflammatory immune compounds were roughly three times lower than normal.

In contrast, artificially activating the cNST reduced pro-inflammatory molecule levels by nearly 70% and increased anti-inflammatory chemical levels almost tenfold.

Similar to a thermostat, this newfound brain circuit helps increase or decrease inflammatory responses to keep the body responding in a healthy manner.

A body–brain circuit that regulates body inflammatory responses, Nature (2024). DOI: 10.1038/s41586-024-07469-y

Part 2

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Comment by Dr. Krishna Kumari Challa 8 hours ago

Scientists identify new brain circuit in mice that controls body's inflammatory reactions

The brain can direct the immune system to an unexpected degree, capable of detecting, ramping up and tamping down inflammation, shows a new study in mice by  researchers.

The brain is the center of our thoughts, emotions, memories and feelings. Thanks to great advances in circuit tracking and single-cell technology, we now know the brain does far more than that. It is monitoring the function of every system in the body.

Future research could identify drugs that can target this newfound brain circuit to help treat a vast range of disorders and diseases in which the immune system goes haywire. This new discovery could provide an exciting therapeutic venue to control inflammation and immunity.

Recent work by scientists is revealing the importance of the body-brain axis, a vital pathway that conveys data between the organs and the brain. For example, they discovered that sugar and fat entering the gut use the body-brain axis to drive the craving and strong appetite for sugary and fatty foods.

They  found all these ways in which the body is informing the brain about the body's current state. 

Part 1

Comment by Dr. Krishna Kumari Challa 9 hours ago

The complementary structural and functional connectivity maps provide a neuroanatomic basis for integrating arousal and awareness in human consciousness. The researchers released the MRI data, brain mapping methods, and a new Harvard Ascending Arousal Network Atlas, to support future efforts to map the connectivity of human consciousness.

This connectivity results suggest that stimulation of the ventral tegmental area's dopaminergic pathways has the potential to help patients recover from coma because this hub node is connected to many regions of the brain that are critical to consciousness.
The human brain connections that they identified can be used as a roadmap to better understand a broad range of neurological disorders associated with altered consciousness, from coma, to seizures, to sudden infant death syndrome (SIDS).

The researchers are currently conducting clinical trials to stimulate the default ascending arousal network in patients with coma after traumatic brain injury, with the goal of reactivating the network and restoring consciousness.

 Brian Edlow et al, Multimodal MRI reveals brainstem connections that sustain wakefulness in human consciousness, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adj4303. www.science.org/doi/10.1126/scitranslmed.adj4303

Part 2

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