Comment

Comment by Dr. Krishna Kumari Challa on May 17, 2023 at 8:33am

Earlier  it was found that intestinal bacteria in centenarians produced unique bile acids that could help keep infections at bay. Other researchers have found that bacteriophages—or viruses that infect bacteria—had an effect on cognition and memory in mice.

 Now the researchers compared the viromes of young adults over 18, older adults over 60, and centenarians aged 100 and over. 

 In centenarians, the team found not only more diverse bacteria and viruses, but also more viruses in the lytic life cycle, during which viruses are active and burst and kill the bacteria they infect—a phase that is more common in infants than adults. At least a quarter of the viruses found in centenarians encoded genes that support key stages of sulfate metabolism. The researchers think this could help sustain the integrity of the mucosal barrier, a highly selective collection of tightly-bound cells that allows the body to absorb nutrients in the gut while keeping bacteria and toxins at bay.

Joachim Johansen et al, Centenarians have a diverse gut virome with the potential to modulate metabolism and promote healthy lifespan, Nature Microbiology (2023). DOI: 10.1038/s41564-023-01370-6

Part 2

Comment by Dr. Krishna Kumari Challa on May 17, 2023 at 8:31am

Viruses in the guts of centenarians may help them resist pathogens

New research suggests that centenarians—people who live to be at least 100—have a diverse collection of viruses in their gut that could help protect them from infectious diseases. The findings, published May 15 in Nature Microbiology, shed light on some of the biological pathways that may help centenarians live long, healthy lives.

In the study, researchers analyzed the viromes—or viral genomes—from 195 individuals from Japan and Sardinia. They found that centenarians  had a greater diversity of bacteria and viruses in their guts.

They also found that viruses found in centenarians increased the ability of the healthy gut bacteria to break down sulfate, which could help preserve the gut's ability to fight bacterial infections.

The study adds to a growing body of evidence showing that the interactions between bacteria, viruses, and fungi in the gut play an important role in preventing age-related conditions.

This snapshot of how the virome interacts with gut microbiomes could tell us about how microbial and viral ecology evolves over the lifetime of a person. This offers an important starting point for uncovering the mechanisms behind how the gut ecosystem maintains health.

Part 1

Comment by Dr. Krishna Kumari Challa on May 17, 2023 at 8:28am

Metastatic spread involves the detachment of tumor cells from a primary tumor, colonization of secondary tissue and growth in a hostile environment. Advanced metastatic tumors are often able to withstand aggressive treatment regimens and represent the leading cause of cancer-associated death.

 The researchers found that the differences are highly dependent on the type of tumor. In some types of tumors, such as pancreatic cancer, the genomic differences between primary and metastatic tumors are subtle. While in others, such as prostate, thyroid and some subtypes of breast cancer, there are very important genomic differences.

In addition, the exhaustive analysis has allowed the researchers to identify recurrent genomic patterns in metastatic tumors such as the presence of high genomic instability, greater enrichment of structural genomic alterations versus point mutations, and the presence of genomic alterations associated with the acquisition of resistance to treatment. However, hardly any driver alterations exclusively associated with the metastatic process could be identified.

Francisco Martínez-Jiménez et al, Pan-cancer whole-genome comparison of primary and metastatic solid tumours, Nature (2023). DOI: 10.1038/s41586-023-06054-z

Francisco Martínez-Jiménez et al, Genetic immune escape landscape in primary and metastatic cancer, Nature Genetics (2023). DOI: 10.1038/s41588-023-01367-1

Part 3

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Comment by Dr. Krishna Kumari Challa on May 17, 2023 at 8:26am

The paper published in Nature describes the overall genomic differences found when comparing primary and metastatic tumors and highlights the fact that the differences are highly dependent on the type of cancer studied, as well as the tumor's exposure to previous anti-tumor treatments.

One could state that this work confirms many observations that were previously done in cancer type-specific studies. However, the pan-cancer nature of the current study demonstrates which processes and mechanisms are shared between tumor types and also quantifies their prevalence per tumor type. Such a systematic analysis and comparison from a genome-wide perspective has never been performed before.

The second study, published in parallel in the journal Nature Genetics, presents an analysis of the genomic alterations that allow tumors to escape the immune system, as well as a comparison of their prevalence in primary and metastatic tumors.

The researchers found that the prevalence of genetic immune escape is highly variable between tumor types and that in certain tumor types only a single mechanism is present, while in others various processes were affected. Furthermore, they showed that there are not many differences between primary and metastatic tumors, indicating that immune evasion is a characteristic that is acquired relatively early in tumor development.

This is the first time a complete tumor genome-wide sequencing dataset has been generated for primary and metastatic tumors of this magnitude. These data are public and available for research, providing a new global resource for further research into the biology and evolution of cancer, as well as the development of new therapies to combat the disease.

Part 2

Comment by Dr. Krishna Kumari Challa on May 17, 2023 at 8:25am

Unique insights into differences between primary and metastatic cancer by large-scale DNA data analyses

Cancer is caused by DNA changes that cause a cell to gradually change from benign to malignant. This can lead to metastases in other parts of the body. By analyzing the DNA data of more than 7,000 patients, the researchers show that there are major differences between primary and metastatic cancer and that there are also tumor types in which the primary tumor and the metastasis hardly differ from one another. By studying the types of DNA changes and the consequences of the changes, important insights into the underlying biological processes were obtained.

Researchers have mapped the DNA changes of the 23 most common tumor types. They have studied the differences in genetic characteristics between the source of the cancer, the primary tumor, and metastatic tumors.

Unique collections of whole genome sequencing data from tumors were used. This enabled the researchers to study in great detail which changes in the tumor had occurred during and after the tumor had developed. The researchers have harmonized and systematically compared the world's largest publicly available data sets of primary tumors (from the international PCAWG consortium with information from ~2,800 patients) and metastatic tumors (Hartwig Medical Database, ~4,400 patients). The results of this research were published May 10 in the journals Nature and Nature Genetics.

Part 1

Comment by Dr. Krishna Kumari Challa on May 16, 2023 at 1:25pm

Mouse Study Reveals Unlikely Connection Between Menthol And Alzheimer's

A new study reports something strange: When mice with Alzheimer's disease inhale menthol, their cognitive abilities improve. It seems the chemical compound can stop some of the damage done to the brain that's usually associated with the disease.

In particular, researchers noticed a reduction in the interleukin-1-beta (IL-1β) protein, which helps to regulate the body's inflammatory response – a response that can offer natural protection but one that leads to harm when it's not controlled properly.

The team behind the study says it shows the potential for particular smells to be used as therapies for Alzheimer's. If we can figure out which odors cause which brain and immune system responses, we can harness them to improve health.

Researchers  have focussed on the olfactory system's role in the immune and central nervous systems, and they have confirmed that menthol is an immunostimulatory odour in animal models.

They observed that short exposures to this substance for six months prevented cognitive decline in the mice with Alzheimer's and, what is most interesting, also improved the cognitive ability of healthy young mice.

https://www.frontiersin.org/articles/10.3389/fimmu.2023.1130044/full

Comment by Dr. Krishna Kumari Challa on May 16, 2023 at 12:24pm

Study reveals 'developmental window' for thinking styles

While people change and learn throughout life, experts recognize that certain formative periods, known as developmental windows, are crucial for acquiring particular skills. For example, using vocalizations and words to interact with people in the first few years of life is critical for children's language learning.

A recent study by an international team suggests there may be a developmental window for reasoning skills as well—the first 25 years of life—and that a person's social, political and economic environment strongly influences how they acquire these skills. Their findings are published in the journal PLOS One.

The researchers found that following the collapse of Romania's authoritarian communist regime in 1989, the rapid increase in education and technology use and the transition from a single, government-controlled source of information to diverse sources had a strong effect on the way people, particularly younger generations, thought about and determined truthfulness, a process known as "epistemic thinking."

Epistemic thinking runs the gamut from absolutist thinking, the belief that only one claim can be right, to multiplist thinking, the belief that more than one claim could be right—it's just a matter of opinion. Finally, evaluativist thinking posits that assertions can be evaluated in terms of both logic and evidence.

Amalia Ionescu et al, The effects of sociocultural changes on epistemic thinking across three generations in Romania, PLOS ONE (2023). DOI: 10.1371/journal.pone.0281785

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Comment by Dr. Krishna Kumari Challa on May 16, 2023 at 11:39am

The researchers studied these solitons by examining the behavior of light that would pass near them. Because they are objects of extreme space-time, they bend space and time around them, which affects the path of light. To a distant observer, these solitons would appear exactly as we predict black holes to appear. They would have shadows, rings of light, the works. Images derived from the Event Horizon Telescope and detected gravitational wave signatures would all behave the same.

It's only once you got close would you realize that you are not looking at a black hole. One of the key features of a black hole is its event horizon , an imaginary surface that if you were to cross it you would find yourself unable to escape. Topological solitons, since they are not singularities, do not feature event horizons.

These topological solitons are incredibly hypothetical objects, based on our understanding of string theory, which has not yet been proven to be a viable update to our understanding of physics. However, these exotic objects serve as important test studies. If the researchers can discover an important observational difference between topological solitons and traditional black holes, this might pave the way to finding a way to test string theory itself.

Pierre Heidmann et al, Imaging topological solitons: The microstructure behind the shadow, Physical Review D (2023). DOI: 10.1103/PhysRevD.107.084042

Part 2

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Comment by Dr. Krishna Kumari Challa on May 16, 2023 at 11:38am

Black holes might be defects in spacetime

A team of theoretical physicists have discovered a strange structure in space-time that to an outside observer would look exactly like a black hole, but upon closer inspection would be anything but: they would be defects in the very fabric of the universe.

Einstein's general theory of relativity predicts the existence of black holes, formed when giant stars collapse. But that same theory predicts that their centers are singularities, which are points of infinite density. Since we know that infinite densities cannot actually happen in the universe, we take this as a sign that Einstein's theory is incomplete. But after nearly a century of searching for extensions, we have not yet confirmed a better theory of gravity.

But we do have candidates, including string theory. In string theory all the particles of the universe are actually microscopic vibrating loops of string. In order to support the wide variety of particles and forces that we observe in the universe, these strings can't just vibrate in our three spatial dimensions. Instead, there have to be extra spatial dimensions that are curled up on themselves into manifolds so small that they escape everyday notice and experimentation. That exotic structure in spacetime gave a team of researchers the tools they needed to identify a new class of object, something that they call a topological soliton. In their analysis they found that these topological solitons are stable defects in space-time itself. They require no matter or other forces to exist—they are as natural to the fabric of space-time as cracks in ice. The research is published in the journal Physical Review D.

Part 1

Comment by Dr. Krishna Kumari Challa on May 16, 2023 at 11:32am

Accretion disk around black holes recreated in the lab

Researchers have created a spinning disk of plasma in a lab, mimicking disks found around black holes and forming stars.

The experiment more accurately models what happens in these plasma disks, which could help researchers discover how black holes grow and how collapsing matter forms stars. As matter approaches black holes it heats up, becoming plasma—a fourth state of matter consisting of charged ions and free electrons. It also begins to rotate, in a structure called an accretion disk. The rotation causes a centrifugal force pushing the plasma outwards, which is balanced by the gravity of the black hole pulling it in.

These glowing rings of orbiting plasma pose a problem—how does a black hole grow if the material is stuck in orbit rather than falling into the hole? The leading theory is that instabilities in magnetic fields in the plasma cause friction, causing it to lose energy and fall into the black hole.

The primary way of testing this has been using liquid metals that can be spun, and seeing what happens when magnetic fields are applied. However, as the metals must be contained within pipes, they are not a true representation of free-flowing plasma.

Now, researchers have used their Mega Ampere Generator for Plasma Implosion Experiments machine (MAGPIE) to spin plasma in a more accurate representation of accretion disks. Details of the experiment are published May 12 in the journal Physical Review Letters.

V. Valenzuela-Villaseca et al, Characterization of Quasi-Keplerian, Differentially Rotating, Free-Boundary Laboratory Plasmas, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.195101

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