Comment

Comment by Dr. Krishna Kumari Challa 3 hours ago

This response doesn't take long at all either. In the experiments run for the study, it took less than a minute for these types of bacteria to realize that blood was nearby and to head towards it.

"We show here that the bacterial attraction response to serum is robust and rapid," write the researchers in their published paper.

The types of bacteria investigated here, from the family Enterobacteriaceae, have already been linked to conditions such as gastrointestinal bleeding and sepsis, particularly where IBD is involved.
The thinking is that these bacteria are latching on to the internal bleeding that often comes with IBD, which is how fatalities can occur.
Knowing more about how bacteria sense the serum in blood, and make use of it, might eventually save lives if treatments are focused on this. By learning how these bacteria are able to detect sources of blood, in the future we could develop new drugs that block this ability.
Bacterial vampirism mediated through taxis to serum:

https://elifesciences.org/reviewed-preprints/93178v2

Comment by Dr. Krishna Kumari Challa 3 hours ago

Some Microbes Are Tiny 'Vampires' With a Deadly Attraction to Human Blood
Researchers have discovered what they describe as 'bacterial vampirism', identifying particular types of bacteria that are attracted to human blood – an attraction that can lead to fatal infections.
Researchers outline how these deadly bacteria are drawn to serum – the liquid part of our blood – because of the nutrients and energy it provides.

That can be a particular problem for people with irritable bowel disease (IBD), where intestinal bleeding can offer gut bacteria a route into the bloodstream. However, these findings also shed light on potential new treatment routes.
Bacteria infecting the bloodstream can be lethal. Some of the bacteria that most commonly cause bloodstream infections actually sense a chemical in human blood and swim toward it.
The researchers used a customized device for injecting tiny amounts of fluid and a high-powered microscope to analyze the interaction of bacteria and blood.

Strains of three bacteria known to cause fatal infections, belonging to the species Salmonella enterica, Escherichia coli, and Citrobacter koseri, were found to be attracted to the human serum.

What's more, the team identified some of the biological interactions: it looks as though the amino acid serine is one of the chemicals the bacteria can sense, seek out, and consume, via particular protein receptors.
Part 1

Comment by Dr. Krishna Kumari Challa 4 hours ago

Keys, wallet, phone: the neuroscience behind working memory

Working memory is a fundamental process that allows us to temporarily store important information, such as the name of a person we’ve just met. However distractions can easily interrupt this process, leading to these memories vanishing. By looking at the brain activity of people doing working-memory tasks, a team have now confirmed that working memory requires two brain regions: one to hold a memory as long as you focus on it; and another to control its maintenance by helping you to not get distracted.

Comment by Dr. Krishna Kumari Challa 5 hours ago

To conduct their experiments, the  researchers used a device called a cryoprobe to injure the fish hearts in ways that mimic heart attacks in humans, then extracted the hearts after certain time frames to learn how the two species responded differently.

They found that Zebrafish have this immune response that is typical of what you might see during a viral infection, called an interferon response. That response is completely absent in medaka.

The study documented differences in immune cell recruitment and behavior, epicardial and endothelial cell signaling, and alterations in the structure and makeup of the heart. For example, medaka lack a certain type of muscle cells that are present in zebrafish.

The study indicates the zebrafish's ability to regenerate has something to do with its immune system, but understanding exactly how would take more research. For example, far more macrophages, specialized immune cells, migrated into the wound site in zebrafish than in medaka.

Unlike medaka, the zebrafish form a transient scar that doesn't calcify into rigid tissue.

What you do with that scar is what matters. Researchers think that the interferon response causes these specialized macrophage cells to come into that wound site and start to promote the growth of new blood vessels.

Over time new muscle replaces the damaged cardiac tissue and the heart heals.

The scientists' hope is that they build this knowledge base in animals that are really accessible and can be studied in incredible detail, then use that knowledge to generate more focused experiments in mammals, and then maybe someday in human patients.

Clayton M. Carey et al, Distinct features of the regenerating heart uncovered through comparative single-cell profiling, Biology Open (2024). DOI: 10.1242/bio.060156

Part 2

Comment by Dr. Krishna Kumari Challa 5 hours ago

Why zebrafish can regenerate damaged heart tissue, while other fish species cannot

A heart attack will leave a permanent scar on a human heart, yet other animals, including some fish and amphibians, can clear cardiac scar tissue and regrow damaged muscle as adults.

Scientists have sought to figure out how special power works in hopes of advancing medical treatments for human cardiac patients, but the great physiological differences between fish and mammals make such inquiries difficult.

So biologists tackled the problem by comparing two fish species: zebra fish, which can regenerate its heart, and medaka, which cannot.

By comparing these two fish that have similar heart morphology and live in similar habitats, researchers could have a better chance of actually finding what the main differences are.

They  identified a few possible explanations, mostly associated with the immune system, for how zebrafish fix cardiac tissue, according to research published in Biology Open.

Their study shed new light on the molecular and cellular mechanisms at play in zebrafish's heart regeneration. It told them these two hearts that look very similar are actually very different.

Both members of the teleost family of ray-finned fish, zebrafish (Danio rerio) and medaka (Oryzias latipes) descended from a common ancestor that lived millions of years ago. Both are about 1.5 inches long, inhabit freshwater and are equipped with two-chamber hearts. Medaka are native to Japan and zebrafish are native to the Ganges River basin.

According to the study, the existence of non-regenerating fish presents an opportunity to contrast the differing responses to injury to identify the cellular features unique to regenerating species. The research team suspect heart regeneration is an ancestral trait common to all teleosts.

Understanding the evolutionary path that led to the loss of this ability in some teleost species could offer parallel insights into why mammals cannot regenerate as adults.

part 1

Comment by Dr. Krishna Kumari Challa yesterday

Researchers crack mystery of swirling vortexes in egg cells

Egg cells are the largest single cells on the planet. Their size—often several to hundreds of times the size of a typical cell—allows them to grow into entire organisms, but it also makes it difficult to transport nutrients and other molecules around the cell. Scientists have long known that maturing egg cells, called oocytes, generate internal, twister-like fluid flows to transport nutrients, but how those flows arise in the first place has been a mystery.

Now, research led by computational scientists, has revealed that these flows—which look like microscopic tornados—arise organically from the interactions of a few cellular components.

Their work, published in Nature Physics, used theory, advanced computer modeling, and experiments with fruit fly egg cells to uncover the twisters' mechanics. The results are helping scientists better understand foundational questions about egg cell development and cellular transport.

In a typical human cell, it takes only 10 to 15 seconds for a typical protein molecule to meander from one side of the cell to the other via diffusion; in a small bacterial cell, this trip can happen in just a single second. But in the fruit fly egg cells studied here, diffusion alone would take an entire day—much too long for the cell to function properly. Instead, these egg cells have developed 'twister flows' that circle around the interior of the oocyte to distribute proteins and nutrients quickly, just as a tornado can pick up and move material much farther and quicker than wind alone. 

Sayantan Dutta et al, Self-organized intracellular twisters, Nature Physics (2024). DOI: 10.1038/s41567-023-02372-1

Comment by Dr. Krishna Kumari Challa yesterday

Discovery of new ancient giant snake in India

A new ancient species of snake dubbed Vasuki Indicus, which lived around 47 million years ago in the state of Gujarat in India, may have been one of the largest snakes to have ever lived, suggests new research published in Scientific Reports. The new species, which reached an estimated length of between 11 and 15 meters, was part of the now extinct madtsoiidae snake family, but represented a distinct lineage that originated in India.

Researchers describe a new specimen recovered from the Panandhro Lignite Mine, Kutch, Gujarat State, India, which dates to the Middle Eocene period, approximately 47 million years ago. The new species is named Vasuki indicus after the mythical snake round the neck of the Hindu deity Shiva and in reference to its country of discovery, India. The authors describe 27 mostly well-preserved vertebra, some of which are articulated, which appear to be from a fully-grown animal.

The vertebrae measure between 37.5 and 62.7 millimeters in length and 62.4 and 111.4 millimeters in width, suggesting a broad, cylindrical body. Extrapolating from this, the authors estimate that V. Indicus may have reached between 10.9 and 15.2 meters in length. This is comparable in size to the longest known snake to have ever lived, the extinct Titanoboa, although the authors highlight the uncertainty around these estimates. They further speculate that V. Indicus's large size made it a slow-moving, ambush predator akin to an anaconda.

The authors identify V. Indicus as belonging to the madtsoiidae family, which existed for around 100 million years from the Late Cretaceous to the Late Pleistocene and lived in a broad geographical range including Africa, Europe, and India. They suggest that V. Indicus represents a lineage of large madtsoiids that originated in the Indian subcontinent and spread via southern Europe to Africa during the Eocene, approximately 56 to 34 million years ago.

Debajit Datta, Largest known madtsoiid snake from warm Eocene period of India suggests intercontinental Gondwana dispersal, Scientific Reports (2024). DOI: 10.1038/s41598-024-58377-0. www.nature.com/articles/s41598-024-58377-0

Comment by Dr. Krishna Kumari Challa yesterday

AI tool predicts responses to cancer therapy using information from each cell of the tumour

With more than 200 types of cancer and every cancer individually unique, ongoing efforts to develop precision oncology treatments remain daunting. Most of the focus has been on developing genetic sequencing assays or analyses to identify mutations in cancer driver genes, then trying to match treatments that may work against those mutations.

But many, if not most, cancer patients do not benefit from these early targeted therapies. In a new study published in the journal Nature Cancer, scientists describe a first-of-its-kind computational pipeline to systematically predict patient response to cancer drugs at single-cell resolution. 

Dubbed PERsonalized Single-Cell Expression-Based Planning for Treatments in Oncology, or PERCEPTION, the new artificial intelligence–based approach dives deeper into the utility of transcriptomics—the study of transcription factors, the messenger RNA molecules expressed by genes that carry and convert DNA information into action.

A tumor is a complex and evolving beast. Using single-cell resolution can allow us to tackle both of these challenges.

PERCEPTION allows for the use of rich information within single-cell omics to understand the clonal architecture of the tumor and monitor the emergence of resistance (In biology, omics refers to the sum of constituents within a cell).

The ability to monitor the emergence of resistance is the most exciting part for researchers. It has the potential to allow them to adapt to the evolution of cancer cells and even modify their treatment strategy.

PERCEPTION: Predicting patient treatment response and resistance via single-cell transcriptomics of their tumors, Nature Cancer (2024). DOI: 10.1038/s43018-024-00756-7

Comment by Dr. Krishna Kumari Challa yesterday

Scientists uncover 95 regions of the genome linked to PTSD

In post-traumatic stress disorder (PTSD), intrusive thoughts, changes in mood, and other symptoms after exposure to trauma can greatly impact a person's quality of life. About 6% of people who experience trauma develop the disorder, but scientists don't yet understand the neurobiology underlying PTSD.

Now, a new genetic study of more than 1.2 million people has pinpointed 95 loci, or locations in the genome, that are associated with risk of developing PTSD, including 80 that had not been previously identified. The study, from the PTSD working group within the Psychiatric Genomics Consortium (PGC—PTSD) together with Cohen Veterans Bioscience, is the largest and most diverse of its kind, and also identified 43 genes that appear to have a role in causing PTSD. The work appears in Nature Genetics.

This discovery firmly validates that heritability is a central feature of PTSD based on the largest PTSD genetics study conducted to date and reinforces there is a genetic component that contributes to the complexity of PTSD.

The findings both confirm previously discovered genetic underpinnings of PTSD and provide many novel targets for future investigation that could lead to new prevention and treatment strategies.

Genome-wide association analyses identify 95 risk loci and provide insights into the neurobiology of post-traumatic stress disorder, Nature Genetics (2024). DOI: 10.1038/s41588-024-01707-9

Comment by Dr. Krishna Kumari Challa on Thursday

To figure it out, the researchers investigated the effect of gamma radiation on a species of tardigrade called Hypsibius exemplaris. They placed tardigrades in a benchtop irradiator that exposed the critters to gamma rays emitted by the beta decay of cesium-137. Since the amount of radiation is known, they were able to expose the tardigrades to specific doses – one lower dose that is within tolerable levels, and a much higher median lethal dose.

To their surprise, although H. exemplaris does have Dsup, the radiation exposure didn't seem to trigger it. In fact, the tardigrades' DNA took a pretty big whack of radiation damage.

Rather than prophylactic protection, the tardigrades ramped up production of DNA repair genes to such a degree that their products became some of the most abundant in their microscopic bodies. By 24 hours after radiation exposure, the tardigrades had repaired most of the DNA broken by ionizing radiation.
In a follow-up, the researchers expressed some of the tardigrade repair genes in a culture of Escherichia coli, and exposed samples of the bacterium to ionizing radiation. Bacteria that had been inoculated with tardigrade genes showed a similar DNA repair ability to that seen in H. exemplaris, but not seen in untreated E. coli.
This suggests, the researchers found, that H. exemplaris is able to sense ionizing radiation, and mount a response that allows it to survive doses that would obliterate other animals.

These animals are mounting an incredible response to radiation, and that seems to be a secret to their extreme survival abilities.

https://www.cell.com/current-biology/abstract/S0960-9822(24)00316-6

• ‹ Previous
• 1
• 2
• 3
• …
• 840
• Next ›
• Page