Comment

Comment by Dr. Krishna Kumari Challa 56 minutes ago

CAR-T therapy drives remission in patient with three autoimmune diseases

For the first time, scientists have used a modern cell therapy called CAR-T to treat a patient with three different life-threatening autoimmune diseases that had resisted years of treatment. The patient, who once required daily blood infusions, has been in remission without needing additional treatment for a year since the CAR-T therapy. The case report, published in Med, suggests that CAR-T therapies can help treat complex and severe autoimmune diseases.
After being sick for more than a decade, the patient is now in treatment-free remission and able to return to an almost normal life. This therapy significantly improved her quality of life.

CD19 CAR-T therapy induces remission in refractory autoimmune hemolytic anemia with ITP and antiphospholipid syndrome, Med (2026). DOI: 10.1016/j.medj.2026.101075

Comment by Dr. Krishna Kumari Challa 1 hour ago

Lowering oxygen levels had a clear effect on the limbs of mouse embryos. Under reduced oxygen, mouse cells closed wounds faster and showed signs of entering a regenerative program. Stabilizing HIF1A produced similar effects, even when oxygen levels remained high.

Low oxygen also changed cell behavior, with skin cells becoming more mobile and altering their mechanical properties. Metabolism shifted toward glycolysis, a process that takes place in low-oxygen states. At the same time, chemical marks on DNA-associated proteins shifted to favor the activation of regeneration-related genes.

Frog tadpoles behaved differently. Their limbs regenerated efficiently across a wide range of oxygen levels, including levels well above those normally found in air. Molecular analysis showed that their cells maintain stable HIF1A activity even when oxygen increases, due to low expression of genes that normally shut this pathway down.

By comparing frogs, axolotls, mice, and human datasets, the team found a consistent pattern. Regeneration-competent amphibians show reduced oxygen-sensing capacity, allowing regenerative programs to be initiated and sustained. Mammals show the opposite pattern. Their cells respond strongly to oxygen and switch regenerative programs off soon after injury.
The results suggest that mammalian limbs retain latent regenerative potential at early stages, depending on how cells respond to environmental signals such as oxygen. This means that adjusting oxygen-sensing pathways might one day improve wound healing or regenerative responses in humans.

Species-specific oxygen sensing governs the initiation of vertebrate limb regeneration, Science (2026). DOI: 10.1126/science.adw8526

Part 2

Comment by Dr. Krishna Kumari Challa 1 hour ago

Why amphibians regenerate limbs but mammals cannot

Some animals can regrow lost body parts. Salamanders and frog tadpoles can rebuild entire limbs after amputation. Mammals cannot. For decades, biologists have tried to understand why. Now a research  team has discovered that oxygen plays a crucial role in limb regeneration. By comparing amputated limbs from frog tadpoles and embryonic mice, the researchers found that the way cells sense oxygen determines whether regeneration can even begin. The study is published in Science.

Limb regeneration begins with wound healing. After amputation, cells at the injury site must rapidly seal the wound and switch into regenerative cell types. In amphibians, this process runs smoothly. In mammals, it stalls early. Wound closure is slow and scar formation takes over, blocking regeneration.

One key difference lies in the environment. Amphibian larvae develop in water, where oxygen levels are lower than in the air. Moreover, many regeneration-competent species live in aquatic environments. Meanwhile, mammalian tissues are typically exposed to higher oxygen levels after injury.

What is unclear is whether this difference has played a direct role in regeneration or is merely a consequence of lifestyle.

The researchers amputated developing limbs from frog tadpoles and mouse embryos and cultured them outside the body under controlled oxygen conditions. Oxygen levels were lowered to match aquatic environments or raised to levels close to air.

They tracked how cells responded by measuring wound closure, cell movement, gene activity, metabolism, and epigenetic states, including changes to DNA packaging. The work focused on HIF1A, a protein that acts as a cellular oxygen sensor. When oxygen is low, HIF1A becomes stable and activates programs that set the stage for wound healing and regeneration.

Comment by Dr. Krishna Kumari Challa 1 hour ago

One DNA letter can trigger complete sex reversal

Researchers have discovered that changing just one letter in DNA can completely alter sex development in mice. In the new study, published in Nature Communications, a single-letter insertion in a non-coding regulatory region caused XX mice, which would normally develop as females, to develop instead as males with testis and male genitalia.

The finding is especially striking because the mutation was not made in a gene itself, but in a distant stretch of DNA that helps control a key developmental gene. The study highlights the major role of the non-coding genome—the 98% of DNA that does not make proteins but helps regulate when and how genes are turned on and off.
This is a remarkable finding because such a tiny change—just one DNA letter out of approximately 2.8 billion—was enough to produce a dramatic developmental outcome. It shows that non-coding DNA can have a profound effect on development and disease.

The mutation was introduced into a regulatory element known as Enh13, which controls the activity of Sox9, a gene essential for testis development. For ovaries to develop normally, Sox9 must be kept turned off. The researchers found that Enh13 acts as a kind of molecular battle site/switch: in males, factors that promote testis development bind to it and activate Sox9 whereas in females, factors that promote ovary development bind to it and repress Sox9.

When the researchers introduced the mutation using CRISPER genome editing, that female repression failed. As a result, Sox9 was activated in XX mice, and testis developed, leading to complete internal and external male development.

The team created several mouse models with very small mutations in Enh13, including a one-base-pair insertion and a three-base-pair deletion. Both mutations caused XX mice to develop testis. The researchers then used cell-line reporter assays to understand how the mutation disrupted the normal regulatory mechanism.

Nature Communications (2026). DOI: 10.1038/s41467-026-71328-9

Comment by Dr. Krishna Kumari Challa 1 hour ago

The 4 Minutes That Will Decide if Artemis II Astronauts Survive

Comment by Dr. Krishna Kumari Challa 2 hours ago

In modern animals, larger eggs typically contain more yolk, providing all the nutrients an embryo needs to develop independently, without parental feeding after hatching.

This strongly suggests that Lystrosaurus did not produce milk for its young, unlike modern mammals. Large eggs also offer another crucial advantage: they are more resistant to drying out. In the harsh, drought-prone environment following the extinction, this would have been a critical survival trait.

The findings further suggest that Lystrosaurus hatchlings were likely precocial, born at an advanced stage of development. These young animals would have been capable of feeding themselves, escaping predators, and reaching reproductive maturity quickly.

In other words, Lystrosaurus succeeded by living fast and reproducing early.
In a world on the brink, this strategy proved unstoppable. This discovery not only provides the first direct evidence of egg-laying in mammal ancestors but also offers a powerful explanation for how Lystrosaurus came to dominate post-extinction ecosystems.

PLOS One (2026). DOI: 10.1371/journal.pone.0345016

Part 2

Comment by Dr. Krishna Kumari Challa 2 hours ago

Mammal ancestors laid eggs

A remarkable new discovery is shedding light on one of the greatest survival stories in Earth's history, and answering a decades-old scientific mystery. Lystrosaurus, a hardy, plant-eating mammal ancestor, rose to prominence in the wake of the End-Permian Mass Extinction some 252 million years ago, the most devastating extinction event our planet has ever experienced.

While countless species vanished, Lystrosaurus not only survived but thrived in a world marked by extreme environmental instability, intense heat, and prolonged droughts.

Now, groundbreaking research published in PLOS ONE reveals a discovery that transforms our understanding of this iconic survivor. An international research team has identified, for the first time, an egg containing an embryo of Lystrosaurus, dating back approximately 250 million years.

This extraordinary fossil represents the first-ever egg discovered from a mammal ancestor, finally answering a long-standing question: Did the ancestors of mammals lay eggs?

The answer is yes!

The researchers suggest these eggs were likely soft-shelled, explaining why they have remained elusive for so long. Unlike the hard, mineralized eggs of dinosaurs, which fossilize readily, soft-shelled eggs rarely preserve, making this find exceptionally rare. But the implications go far beyond reproduction.

The study reveals that Lystrosaurus laid relatively large eggs for its body size.

Part 1

Comment by Dr. Krishna Kumari Challa 3 hours ago

"Ghost Murmur"

Comment by Dr. Krishna Kumari Challa 23 hours ago

Can drugs skip the blood-brain barrier?
Researchers have skipped the blood-brain barrier altogether by injecting drug-loaded nanoparticles into the space between skull bone layers. Immune cells then ferried these nanoparticles into the brain. In a randomized study of 20 stroke patients, clinical outcomes were better in the group where treatment was also injected through the skull, compared to the standard of care. The ability to skip the blood-brain barrier in its entirety could be massively useful for treating many brain-based disorders, but there’s a lot more work in store, writes medicinal chemist Derek Lowe.

https://www.sciencedirect.com/science/article/pii/S0092867425014217...

Comment by Dr. Krishna Kumari Challa 23 hours ago

Loss of microbiota alters the profile of cells that protect the intestinal wall, experiments reveal

Research by scientists has made significant progress in understanding the relationship between gut microbiota and intestinal cells. The study, published in the journal Gut Microbes, showed how microbiota and the compounds it produces, such as butyrate, influence the functioning of cells that line the large intestine. This intestinal layer is in close contact with bacteria and produces mucus that contributes to its barrier function, helping to prevent bacteria from entering the body.
Loss of gut microbiota increases the abundance of a dual-function intestinal epithelial cell capable of both mucus secretion and nutrient absorption, a process regulated by microbiota-derived butyrate and its receptor GPR109A. This cell population expands in conditions of dysbiosis or aging, indicating adaptive epithelial plasticity and altered barrier function.
Among the findings is a description of the dual function of a cell that was previously thought to be exclusively mucus-secreting. The researchers discovered that the cell also absorbs nutrients and that its abundance in the epithelium is regulated by signals from the gut microbiota. The number of these cells increases when the gut microbiota is reduced.

The abundance of this cell is regulated by the production of butyrate—a compound resulting from the fermentation of dietary fiber—and its receptor, GPR109A. The more butyrate produced, the fewer of these cells there are.

This study paves the way for a better understanding of the role of microbiota and its metabolites in conditions such as inflammatory bowel disease and in developing treatments. Furthermore, the study demonstrates how the integrity of the intestinal wall can change, particularly in older individuals.
When the microbiota is reduced, the large intestine—which under normal conditions prioritizes mucus production—begins to express characteristics linked to nutrient absorption typically associated with the small intestine. We still don't know why this happens, but this change may be related to the expansion of dual-function cells and represent an adaptive response to the decrease in bacteria in this portion of the intestine, say the researchers.

Matheus de T. Moroti et al, Historical shifts, geographic biases, and biological constraints shape mammal species discovery, Journal of Systematics and Evolution (2026). DOI: 10.1111/jse.70040

• ‹ Previous
• 1
• 2
• 3
• …
• 1214
• Next ›
• Page