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Comment by Dr. Krishna Kumari Challa 12 hours ago

Super stem cells become better versions of themselves by changing their diet

In a new study, researchers  have successfully created stem cells that are better at developing into other cell types, like a younger, fitter version of themselves—by changing their diet. These stem cells are better than normal stem cells at creating specialized cells like liver, skin or nerve cells, which is a core trait of stem cells.

Researchers showed that by changing their diet, the stem cells can rejuvenate and turn into 'super stem cells.' It forces them to metabolize their energy in a different way than they normally would, and that process essentially reprograms the stem cells.

The net result is that they behave like they are from an earlier stage of development, which enhances their ability to develop, or differentiate, into other types of cells.

Specifically, the researchers changed what type of sugar the stem cells have available in the medium they grow in. The cells use the sugar to generate energy.

"What is really striking is that they're not just better at differentiating, but they stay fit and keep healthy much better over time compared to stem cells in standard culture conditions. And it is done with a relatively simple method.

Altering metabolism programs cell identity via NAD+-dependent deacetylation, The EMBO Journal (2025). DOI: 10.1038/s44318-025-00417-0

Comment by Dr. Krishna Kumari Challa yesterday

UN warns vaccine-preventable diseases on the rise globally

Outbreaks of vaccine-preventable diseases such as measles, meningitis, and yellow fever are on the rise globally amid misinformation and cuts to international aid, the United Nations and the Gavi vaccine alliance warned this week.

Vaccines have saved more than 150 million lives over the past five decades. Funding cuts to global health have put these hard-won gains in jeopardy.

The increasing outbreaks around the world are "putting lives at risk and exposing countries to increased costs in treating diseases."

Measles, for example, is making an "especially dangerous comeback," with cases rising every year since 2021 and reaching an estimated 10.3 million in 2023, which is a 20% increase since 2022.

The organizations believe that the trend is likely to have continued into 2024 and 2025.

In the past 12 months, 138 countries have reported measles cases, with 61 experiencing large or disruptive outbreaks—the highest number observed in any 12-month period since 2019, according to the statement.

The joint statement was signed by the World Health Organization, the United Nations children's fund UNICEF, and Gavi, and was released Wednesday at the start of World Immunization Week, which runs April 24-30.

Cases of meningitis and yellow fever have also increased significantly in Africa in 2024, it said.

The spikes are taking place amid rising misinformation, population growth and humanitarian crisis.

https://www.who.int/news/item/24-04-2025-increases-in-vaccine-preve...

Comment by Dr. Krishna Kumari Challa yesterday

Blocking a master regulator of immunity eradicates liver tumors in mice

A protein identified nearly 40 years ago for its ability to stimulate the production of red blood cells plays a  critical role in dampening the immune system's response to cancer.

Blocking the activity of the protein turns formerly "cold," or immune-resistant, liver tumors in mice into "hot" tumors teeming with cancer-fighting immune cells. When combined with an immunotherapy that further activates these immune cells against the cancer, the treatment led to complete regression of existing liver tumors in most mice. Treated animals lived for the duration of the experiment. In contrast, control animals survived only a few weeks.

This is a fundamental breakthrough in our understanding of how the immune system is turned off and on in cancer.

Although the work was completed in mice, there are strong indications that the protein, erythropoietin or EPO, plays a similar role in many types of human cancers.

 David Kung-Chun Chiu et al, Tumor-derived erythropoietin acts as an immunosuppressive switch in cancer immunity, Science (2025). DOI: 10.1126/science.adr3026. www.science.org/doi/10.1126/science.adr3026

Comment by Dr. Krishna Kumari Challa on Thursday

The current study, which included fewer than 50 participants, was built on previous research conducted in Italy. Researchers compared the levels of micronanoplastics found in the carotid arteries of three groups: people with healthy arteries; those with plaque but no symptoms; and those experiencing symptoms due to plaque buildup.

Researchers also compared plaques with low and high plastic levels to assess the effects of micronanoplastics on markers of inflammation, the gene activity of immune cells called macrophages and stem cells that help stabilize plaque.

The analysis found that the concentration of micronanoplastics in carotid arteries was:

16 times higher (895 micrograms/gram vs. 57 micrograms/gram) in plaque among people without symptoms compared to the levels found in artery walls of deceased tissue donors of similar age with no plaque; and
51 times higher (2,888 micrograms/gram vs. 57 micrograms/gram) in plaque from people who had experienced stroke, mini-stroke or temporary loss of vision due to blockage of blood flow to the retina, in comparison to samples from age-matched, deceased tissue donors.
Comparing high-plastic and low-plastic plaque levels, the analysis found:

no link between the amount of micronanoplastics and signs of sudden inflammation; and
differences in gene activity in plaque-stabilizing cells and less activity in anti-inflammatory genes of plaque macrophage immune cells.
"These findings indicate that the biological effects of micronanoplastics on fatty deposits are more complex and nuanced than simply causing sudden inflammation.

https://professional.heart.org/en/meetings/vascular-discovery-from-...

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

Tiny plastic particles found in artery-clogging plaque in the neck

People with plaque in the blood vessels of their neck have a higher amount of tiny plastic particles in those vessels compared to people with healthy arteries. This increase was significantly higher in people who had experienced a stroke, mini-stroke or temporary loss of vision due to clogged blood vessels, according to preliminary research presented at the American Heart Association's Vascular Discovery 2025 Scientific Ses..., April 22–25 .

Micronanoplastics are tiny pieces of plastic created in industrial processes or from larger plastic objects as they degrade in the ocean or the soil. Micronanoplastics are not uniform in size and are a mixture of micro and nano plastic sizes.

While microplastics are sometimes visible at less than 5 millimeters in size, nanoplastics are microscopic, less than 1,000 nanometers across. This makes them more easily dispersed and able to penetrate cells and tissues in living organisms. Researchers suggest that terminology should gradually transition to nanoplastics because that is more precisely what is being studied.

These types of plastics are commonly found in the environment, especially in ocean garbage patches. Over many years, these plastics break down, mix into the soil and water, and can build up in the food chain.

Many people think that micro and nanoplastics mainly come from using plastic utensils, cutting boards, packaging, water bottles and other plastic items. However, the main source is the food and water we eat and drink.

In 2024, researchers in Italy reported finding micronanoplastics in plaque from some people without symptoms who underwent surgery to remove carotid artery plaque.

Symptoms caused by carotid plaque buildup may include stroke, mini-stroke or temporary blindness. Followed for almost three years after surgery, people with micronanoplastics in their carotid plaque were significantly more likely to die or to have a non-fatal heart attack or stroke.

Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

The world's biggest companies have caused $28 trillion in climate damage

The world's biggest corporations have caused $28 trillion in climate damage, a new study estimates as part of an effort to make it easier for people and governments to hold companies financially accountable.

A research team came up with the estimated pollution caused by 111 companies, with more than half of the total dollar figure coming from 10 fossil fuel providers: Saudi Aramco, Gazprom, Chevron, ExxonMobil, BP, Shell, National Iranian Oil Co., Pemex, Coal India and the British Coal Corporation.

The researchers figured that every 1% of greenhouse gas put into the atmosphere since 1990 has caused $502 billion in damage from heat alone, which doesn't include the costs incurred by other extreme weather such as hurricanes, droughts and floods. People talk about making polluters pay, and sometimes even take them to court or pass laws meant to rein them in. The study is an attempt to determine the causal linkages that underlie many of these theories of accountability.

Christopher W. Callahan et al, Carbon majors and the scientific case for climate liability, Nature (2025). DOI: 10.1038/s41586-025-08751-3

Comment by Dr. Krishna Kumari Challa on Thursday

Repair in mammals often proceeds through scarring, a process that rapidly seals wounds without restoring original tissue architecture. This may reflect an evolutionary trade-off in larger or more complex organisms, where fast tissue sealing through fibrosis can ensure immediate survival, even at the cost of long-term function or structural integrity.

Greater understanding of the requirements for regeneration in worms and other regenerating species brings science closer to the goal of one day reverse-engineering regenerative responses in therapeutic settings.

Clare L.T. Booth et al, Developmental onset of planarian whole-body regeneration depends on axis reset, Current Biology (2025). DOI: 10.1016/j.cub.2025.03.065

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

Stem cells need positional signals to drive regeneration

Scientists  have discovered that Schmidtea polychroa, a flatworm capable of regenerating lost tissue, develops this ability progressively during early life stages. Whole-body regeneration emerges during specific embryonic and juvenile stages, with head regeneration limited until the organism gains the capacity to reset its body's main axis. Stem-like cells are necessary for tissue growth yet insufficient on their own to trigger full regeneration.

Regeneration encompasses biological processes that replace tissues during normal maintenance or after injury. Some aquatic invertebrates such as hydrozoans, planarians, and acoels can regenerate entire bodies from mere tissue fragments. Certain fish, amphibians, and reptiles can regrow lost appendages.

Regenerative abilities change throughout an organism's life. In many species, embryos and juveniles regenerate more readily than adults. Aging has been associated with reduced regeneration in structures such as the mouse heart and digit tip, Xenopus limbs and tail, and Drosophila imaginal disks.

Even highly regenerative animals like tunicates and sponges show reduced ability as they age. These changes have been linked to stem cell exhaustion, loss of cellular plasticity, epigenetic alterations, and metabolic shifts. Gains in regenerative ability during adulthood have also been observed in sponges, crinoids, ctenophores, annelids, tunicates, and some vertebrates such as Xenopus tadpoles and certain lizards.

Planarian flatworms retain whole-body regenerative capacity into adulthood. Their regenerative ability depends on adult pluripotent stem cells, called neoblasts, which are distributed throughout the body. Neoblasts respond to injury through position-specific signaling from surrounding tissues and generate new tissues during maintenance, asexual reproduction, and regeneration.

Research Results reveal that whole-body regeneration is not an inherent, default property of possessing stem cells but instead depends on developmental cues that enable axis reset. The ability to regenerate a head only emerged after embryos gained competence to reset anterior-posterior polarity. Fragments containing functional progenitor cells still failed to regenerate unless specific polarity signals were activated.

Axis reset emerges as a critical gatekeeper in whole-body regeneration, with direct manipulation of signaling pathways enabling regeneration in fragments previously unable to recover. Findings point to regeneration as a conditional capability, one that may be switched on or off depending on developmental state and molecular context.

Broader strategies to induce regeneration in less regenerative animals may require restoring not just stem cell presence, but also the injury-induced cues that trigger polarity establishment and tissue identity. Results may challenge assumptions that regenerative loss is irreversible and suggest new targets for restoring tissue-forming potential.

Mammals, including humans, have limited regenerative capacity and are restricted to replacing select tissues and cell types.

Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

Lesions on the left iliac spine of 6DT19. Credit: PLOS One (2025). DOI: 10.1371/journal.pone.0319847

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

First skeletal evidence of gladiator bitten by lion in Roman period

A study has uncovered the first physical evidence of human-animal gladiatorial combat in the Roman period.

The research, published in PLOS One, presents compelling skeletal evidence of a human victim attacked by a large carnivorous animal, likely within the context of Roman-era spectacle combat. It was conducted by an international team of archaeologists and osteologists.

While images of gladiators being bitten by lions have appeared in ancient mosaics and pottery, this is the only convincing skeletal evidence using forensic experiments anywhere in the world of bite marks produced by the teeth of a large cat, such as a lion.

The findings center on a single skeleton discovered in a Roman-period cemetery outside York in England, a site believed to contain the remains of gladiators. The individual's bones exhibited distinct lesions that, upon close examination and comparison with modern zoological specimens, were identified as bite marks from a large feline species.

The bite marks on the pelvis of the skeleton represent the first osteological confirmation of human interaction with large carnivores in a combat or entertainment setting in the Roman world.

For years, our understanding of Roman gladiatorial combat and animal spectacles has relied heavily on historical texts and artistic depictions. This discovery provides the first direct, physical evidence that such events took place in this period, reshaping our perception of Roman entertainment culture in the region.

Unique osteological evidence for human-animal gladiatorial combat in Roman Britain, PLOS One (2025). DOI: 10.1371/journal.pone.0319847. journals.plos.org/plosone/arti … journal.pone.0319847

Part 1

Part 2 ( on top of this contain pics)

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