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Comment by Dr. Krishna Kumari Challa on Tuesday

Kidney fibrosis linked to molecule made by gut bacteria

A molecule made by bacteria in the gut can hitch a ride to the kidneys, where it sets off a chain reaction of inflammation, scarring and fibrosis—a serious complication of diabetes and a leading cause of kidney failure—according to a new study from researchers .

After finding high levels of corisin—a small peptide produced by Staphylococcus bacteria in the gut—in the blood of patients with diabetic kidney fibrosis, the researchers used computer simulations and tissue and mouse experiments to track how corisin affects the kidneys, how it gets there from the gut, and a possible method of countering it with antibody treatment.

These  new findings suggest corisin is indeed a hidden culprit behind progressive kidney damage in diabetes, and that blocking it could offer a new way to protect kidney health in patients.

Taro Yasuma et al, Microbiota-derived corisin accelerates kidney fibrosis by promoting cellular aging, Nature Communications (2025). DOI: 10.1038/s41467-025-61847-2

Comment by Dr. Krishna Kumari Challa on Tuesday

Cells from the spleen found to play a surprising role after heart attack

After a person survives a heart attack, the heart has a brief window of time in which it can heal if the right circumstances exist. But most of the time, scar tissue forms in the areas that lacked oxygen during the heart attack. This scar tissue impairs heart function, which can worsen into heart failure, reducing quality of life and increasing the risk of early death.

A new study has identified a surprising role for the spleen—a small organ near the ribs that filters blood and fights infections—in helping the heart heal after a heart attack.

The research, published in Circulation, demonstrated in mice that specific immune cells called marginal metallophilic macrophages, which originate in the spleen, travel from the spleen to the heart and support a healing response after a heart attack.

Using mouse models, single-cell RNA sequencing and other advanced techniques, the researchers established that these specialized macrophages from the spleen help clear damaging immune cells, suppress inflammation and activate genes that help repair the injured cardiac tissue following a heart attack.

To assess whether the same thing occurs in humans, the researchers measured levels of marginal metallophilic macrophages in blood samples collected from people upon their hospital admission due to a heart attack. The researchers compared these levels with those of cardiac patients who had coronary artery disease but had not recently had a heart attack. The researchers  found that levels of the specialized macrophages were higher in patients who had just had a heart attack.

The researchers also demonstrated that they could boost the numbers of these specialized immune cells in mice with an experimental drug, and that doing so improved the healing and anti-inflammatory effects. This medical intervention is not yet in clinical trials, but it suggests a possible future cardiac immunotherapy targeting the spleen to prevent heart failure in patients who survive a heart attack.

 Mohamed Ameen Ismahil et al, Splenic CD169⁺Tim4⁺ Marginal Metallophilic Macrophages Are Essential for Wound Healing After Myocardial Infarction, Circulation (2025). DOI: 10.1161/CIRCULATIONAHA.124.071772

Comment by Dr. Krishna Kumari Challa on Tuesday

This human type, which the researchers called "Nesher Ramla Homo" (after the archaeological site near the Nesher Ramla factory where it was found), encountered Homo sapiens groups that began leaving Africa about 200,000 years ago, and according to the current study's findings, interbred with them.

The child from the Skhul Cave is the earliest fossil evidence in the world of the social and biological ties forged between these two populations over thousands of years. The local Neanderthals eventually disappeared when they were absorbed into the Homo sapiens population, much like the later European Neanderthals.

The researchers reached these conclusions after conducting a series of advanced tests on the fossil.
The fossil they studied is the earliest known physical evidence of mating between Neanderthals and Homo sapiens.
The current study reveals that at least some of the fossils from the Skhul Cave are the result of continuous genetic infiltration from the local—and older—Neanderthal population into the Homo sapiens population.

Bastien Bouvier et al, A new analysis of the neurocranium and mandible of the Skhūl I child: Taxonomic conclusions and cultural implications, L'Anthropologie (2025). DOI: 10.1016/j.anthro.2025.103385

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

Earliest evidence discovered of interbreeding between Homo sapiens and Neanderthals

An international study by researchers provides the first scientific evidence that Neanderthals and Homo sapiens had biological and social relations, and even interbred for the first time, in the Land of Israel.

The research team found a combination of Neanderthal and Homo sapiens traits in the skeleton of a five-year-old child discovered about 90 years ago in the Skhul Cave on Mount Carmel. The fossil, estimated to be about 140,000 years old, is the earliest human fossil in the world to display morphological features of both of these human groups, which until recently were considered two separate species.

Genetic studies over the past decade have shown that these two groups exchanged genes.

Even today, 40,000 years after the last Neanderthals disappeared, part of our genome—2% to 6%—is of Neanderthal origin. But these gene exchanges took place much later, between 60,000 to 40,000 years ago.

In the new study, the researchers were dealing with a human fossil that is 140,000 years old. They  show that the child's skull, which in its overall shape resembles that of Homo sapiens—especially in the curvature of the skull vault—has an intracranial blood supply system, a lower jaw, and an inner ear structure typical of Neanderthals.

For years, Neanderthals were thought to be a group that evolved in Europe, migrating to the Land of Israel only about 70,000 years ago, following the advance of European glaciers.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Scientists discover rare freshened water beneath the seafloor

How did freshened water end up beneath the New England Shelf miles offshore?

Researchers are attempting to answer the question by studying samples collected from three sites off the coast of Nantucket. Sampling of this offshore freshened groundwater to the extent that they can make comprehensive geochemical assessments of its history, including its age, is unprecedented in scientific ocean drilling.

The salinity levels of sediments below the seafloor are typically close to those in the overlying ocean, yet offshore New England, the subseafloor contains an unusually large reservoir of freshened water.

The sheer freshness of the water, which was close to drinking water limits, was a surprise.

The cores will be archived and made accessible for further scientific research for the scientific community after a one-year moratorium period. All expedition data will be open access and resulting outcomes will be published.

https://www.uri.edu/news/2025/05/gso-professor-joins-expedition-to-...

Comment by Dr. Krishna Kumari Challa on Saturday

Scientists Have Just Created The Most Synthetic Life Form Ever

Scientists have created a bacteria with a genetic code more streamlined – and more meddled with – than any other life on Earth. This bacteria, a synthetic Escherichia coli called Syn57, has been engineered to build its body using just 57 of the 64 'codons' that have served all known organisms for billions of years. The recipe for life is written in a language that uses 64 different codons, each composed of a triplet of nucleotides. It's the long sentences of 'three-letter' codons that make up our DNA and RNA. They provide our cells with the essential instructions to translate ordinary matter into the building blocks of life, amino acids, which are threaded in sequence to form proteins. When a cell is building proteins, it 'reads' the codon sequence, written using those 64 nucleotide triplets, to know which amino acids to add next, and when to stop.By engineering the entire genome from scratch, the researchers set out to eliminate four of the six codons associated with the amino acid serine, two of the four alanine codons, and one 'stop' codon. Where these redundant codons appeared in the bacteria's genome, the researchers substituted them with synonymous codons that give the same instructions. This required more than 101,000 changes to the genetic code. These were planned out on the computer first, in 100-kilobyte fragments, and then came the arduous work of assembling the gene. To make sure they weren't inserting fundamentally harmful changes into the microbes, the team tested small fragments of the synthetic genome in living bacteria bit by bit, eventually stitching it all together to form the final, entirely synthetic strain.

https://www.science.org/doi/10.1126/science.ady4368

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Comment by Dr. Krishna Kumari Challa on Saturday

Croatian Freediver Shatters Record For Longest-Held Breath
This year, on June 14, Croatian freediver Vitomir Maričić set a world record when he held his breath for 29 minutes and 3 seconds.

That’s longer than a bottlenose dolphin, and 5 minutes longer than the previous Guinness World Record holder.
Nearly half an hour without air is mind boggling. That's roughly twice as long as a bottlenose dolphin is thought to hold its breath.
With each breath, a seal can replace 90 percent of the air in its lungs – but our species can only replace 20 percent. To keep up, we need more breaths to fill our lungs with fresh air.

To get as much oxygen into his body as it could possibly carry, Maričić inhaled pure oxygen for 10 minutes before the attempt.
This increased the oxygen dissolved in his blood plasma, which is a crucial reservoir for the body's tissues.

On an Instagram reel, Maričić explains that he started his record-breaking attempt with nearly five times more oxygen in his body than usual. Without that, he never could have lasted so long.

https://www.sciencealert.com/croatian-freediver-shatters-record-for...

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Comment by Dr. Krishna Kumari Challa on Saturday

Hidden body fat linked to faster heart aging

Excessive amounts of visceral fat—the hidden fat surrounding organs—is linked with faster aging of the heart, a new study has found.

Aging is the biggest risk factor for heart disease, but why some people age faster than others isn't fully understood. The scientists leading the research say that visceral body fat could play an important role in accelerating aging of the heart and blood vessels. This type of fat is known to be harmful to health and this study now links it to faster heart aging.

In the study, published in the European Heart Journal, the scientists analyzed data from 21,241 participants in the UK Biobank, which includes whole-body imaging to map the amount of fat and where it is located in the body.

The UK Biobank data also includes detailed imaging of the heart and blood vessels. Artificial intelligence was used to analyze these images to capture signs of organ aging—such as tissues becoming stiff and inflamed. An individual was given a "heart age" which can be compared to their actual age at the time of the scan.

The researchers found that faster heart aging was linked to having more visceral adipose tissue. Visceral adipose tissue is fat found deep inside the abdomen around organs such as the stomach, intestines, and liver. This type of fat cannot be seen from the outside, and some people can have large amounts of visceral fat despite having a healthy weight.

The researchers found signs on blood tests that visceral fat is linked to increased inflammation in the body—which is a potential cause of premature aging.

They also found differences between the sexes. Male-type fat distribution (fat around the belly, often called 'apple' shaped) was particularly predictive of early aging in men.

In contrast, a genetic predisposition to female-type fat (fat on the hips and thighs, often called "pear" shaped) was protective against heart aging in women.

The researchers also found a link between higher estrogen levels in premenopausal women and a slowing of heart aging, which they suggest could indicate a role for hormones in protecting against heart aging.

Declan P O'Regan et al, Sex-specific body fat distribution predicts cardiovascular ageing, European Heart Journal (2025). DOI: 10.1093/eurheartj/ehaf553

Comment by Dr. Krishna Kumari Challa on Saturday

Rethinking phototherapy: Why skin color matters for infant jaundice treatment

Jaundice is one of the most common medical issues in newborns, affecting nearly 80% of full-term infants in their first days of life. The condition occurs when excess bilirubin, a yellow pigment formed as red blood cells break down, builds up in the body. While mildcases usually resolve on their own, dangerously high bilirubin levels can cause brain damage or even death. The standard treatment, phototherapy, uses blue light to break bilirubin down into forms the body can excrete.

A theoretical study recently published in Biophotonics Discovery used computer modeling to examine how skin color and other skin properties might influence how much therapeutic light reaches target tissues.

Researchers employed advanced computer simulations to model light penetration in newborn skin. The simulations incorporated factors such as skin pigmentation, hemoglobin levels, bilirubin concentration, skin thickness, and treatment light wavelength.  

Since specific data on skin color variations in newborns have not yet been reported, the researchers based their pigmentation parameters on established measurements from adult skin data. The modeling predicted that skin pigmentation would have the largest effect on light penetration.

Compared with light-skinned infants, the simulations suggested dark-skinned infants might receive up to 5.7 times less effective light dose under identical settings. This theoretical difference translated into predicted bilirubin reductions of about 40.8% for light-skinned newborns after 24 hours of phototherapy, versus 25.6% for dark-skinned newborns. The model also predicted that epidermal thickness and bilirubin levels would influence treatment effectiveness, though to a lesser degree.

The simulations further suggested that optimal treatment wavelength might vary by skin color. While light-skinned infants were predicted to respond best at around 460 nanometers (nm), dark-skinned infants showed better theoretical responses at slightly longer wavelengths, around 470 nm. The researchers propose that a compromise wavelength near 465 nm could provide more consistent results across skin tones.

Current phototherapy guidelines use a standardized approach without adjustments for skin tone. While phototherapy generally demonstrates effectiveness across populations, the authors note their theoretical findings suggest it might be less efficient in darker-skinned infants, potentially affecting treatment duration and outcomes.

Highlighting the importance of obtaining more fundamental insight into newborn skin pigmentation, they also emphasize the critical need for clinical studies to validate these computational predictions and determine whether actual bilirubin reduction varies by skin color in real patients.

 Alida Johanna Dam-Vervloet et al, Effect of skin color and other skin properties on the delivered light dose in phototherapy for neonatal hyperbilirubinemia, Biophotonics Discovery (2025). DOI: 10.1117/1.BIOS.2.3.032508

Comment by Dr. Krishna Kumari Challa on Saturday

Breast cancer drug side effects: Study reveals how tamoxifen raises risk of secondary tumors in uterus

An international research team has identified a previously unknown mechanism by which the breast cancer drug tamoxifen can increase the risk of secondary tumors in the uterus.

The study shows that tamoxifen directly activates a key cellular signaling pathway (known as PI3K) a central driver in the development of sporadic uterine cancers, thereby challenging previously accepted models of therapy-related cancer development.

Since its introduction in the 1970s, tamoxifen has significantly improved survival rates for millions of patients with estrogen receptor–positive breast cancer. However, alongside its life-saving benefits, tamoxifen has also been linked—though rarely—to an elevated risk of uterine cancer. Until now, the precise molecular cause of this effect has remained unclear.

The new findings, published in Nature Genetics, reveal the mechanism: in tamoxifen-associated uterine carcinomas, mutations in the cancer-related gene PIK3CA—which are very common in spontaneously arising uterine tumors and lead to the activation of the PI3K signaling pathway—occur significantly less frequently. Instead, tamoxifen itself takes on the role of a signal activator of the PI3K pathway, making such mutations unnecessary.

Kirsten Kübler et al, Tamoxifen induces PI3K activation in uterine cancer, Nature Genetics (2025). DOI: 10.1038/s41588-025-02308-w

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