Comment

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 2:18pm

Bacterial duo eliminates tumors without immune system help in new cancer therapy

A  research team has developed an immune-independent bacterial cancer therapy using a novel microbial consortium called AUN.

Cancer immunotherapy originated in 1868 when the German physician Busch reported a case of a cancer patient who was intentionally infected with bacteria and subsequently cured. In 1893, Dr. William Coley proposed the use of bacteria for cancer treatment, and immunotherapies have been evolving into modern treatments such as checkpoint inhibitors and CAR-T cells for over 150 years. While powerful, these approaches fundamentally depend on immune cells—making them ineffective for many cancer patients with compromised immune systems due to chemotherapy or radiotherapy.

The newly developed AUN therapy overturns this long-standing limitation. The research is published in Nature Biomedical Engineering.

AUN is composed of two naturally occurring bacteria:

• Proteus mirabilis (A-gyo), a tumor-resident microbe
• Rhodopseudomonas palustris (UN-gyo), a photosynthetic bacterium

Working in perfect synergy, these AUN bacteria produce exceptional tumor eradication in both murine and human cancer models, even in immunocompromised environments—all without the help of immune cells. The therapy exhibits high biocompatibility and minimal side effects, including suppression of cytokine release syndrome (CRS).

Part 1

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 2:14pm

Study finds Ozempic may weaken muscles even as muscle size remains stable

As use of the popular anti-diabetic and weight-loss drug Ozempic skyrockets, so have concerns about the medication's side effects. One such side effect is loss of "lean mass"—body weight that isn't fat—raising concerns that Ozempic could be reducing muscle mass and strength.

New research in mice suggests that muscle mass changes less than expected, but muscles may still get weaker, pointing out an urgent need for clinical studies to pin down the full effects of the popular medications.

Researchers found that Ozempic-induced weight loss did decrease lean mass by about 10%. Most of this lost weight wasn't from skeletal muscles but instead from other tissues like the liver, which shrank by nearly half. The researchers emphasize that more research is needed to determine whether similar changes to organ size occur in humans—and whether those changes come with any risks.

Interestingly, when the researchers tested the amount of force the mice's muscles could exert, they found that, for some muscles, strength decreased as the mice lost weight, even when the size of the muscle stayed roughly the same. For other muscles, strength was unchanged. It's unknown how weight loss drugs affect this balance in people, the researchers say.

A potential loss of strength when taking Ozempic may be of particular concern for adults over the age of 60, who are at higher baseline risk for muscle loss and reduced mobility. "The loss of physical function is a strong predictor of not just quality of life but longevity," they add.

However,  mice and humans gain and lose weight in different ways and unless tested in humans, we can't apply the same results to human beings. 

Unexpected effects of semaglutide on skeletal muscle mass and force-generating capacity in mice, Cell Metabolism (2025). DOI: 10.1016/j.cmet.2025.07.004. www.cell.com/cell-metabolism/f … 1550-4131(25)00331-6

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 2:04pm

Science in History's help

Napoleon's doomed retreat: DNA from Vilnius mass grave reveals signs of foodborne and lice-borne fever

Institut Pasteur and partner institutions report genetic evidence of Salmonella enterica lineage Para C and Borrelia recurrentis in Napoleonic soldiers from Vilnius, indicating paratyphoid fever and louse-borne relapsing fever were present during the 1812 retreat.

Napoleon assembled about 500,000–600,000 soldiers to invade Russia in 1812. After arriving in Moscow without decisively defeating the Russian army, the Napoleonic forces found themselves isolated in a ruined city and initiated a retreat to establish winter encampments along the border with Poland.

Retreat from Russia spanned October 19 to December 14, 1812 and resulted in massive losses attributed by historians to cold, hunger, and diseases. Physicians and officers documented typhus, diarrhea, dysentery, fevers, pneumonia, and jaundice.

Previous reports described body lice in Vilnius remains and PCR-based claims of Rickettsia prowazekii and Bartonella quintana using short fragments, alongside Anelloviridae in other soldiers from Kaliningrad.

In the study, "Paratyphoid Fever and Relapsing Fever in 1812 Napoleon's Devastated Army," published on the pre-print server bioRxiv, researchers recovered and sequenced ancient DNA from the teeth of soldiers who likely died from infectious diseases to identify pathogens that could have contributed to their deaths.

The sampling drew on 13 intact teeth from different individuals recovered from a mass grave in Vilnius, Lithuania associated with the December 1812 retreat, from a site with a minimum of 3,269 exhumed individuals. No battle trauma was observed at the site.

Initial analysis flagged fourteen possible pathogens. Salmonella enterica and Borrelia recurrentis showed the strongest signals. Four soldiers (87A, 92B, 95A and 97B) yielded between roughly 30 and 970 unique DNA fragments matching the Paratyphi C strain, with read-mismatch patterns indicating authentic ancient bacterial DNA.

Sample 93A produced about 4,060 unique fragments covering the chromosome and all seven plasmids of B. recurrentis, while 92B contributed around 320 unique reads and 18 confirmed hits after detailed filtering.

Phylogenetic placement positioned all Salmonella sequences firmly within the Paratyphi C lineage, a pathogen known to cause paratyphoid fever. No authenticated DNA matches Rickettsia prowazekii or Bartonella quintana. While no authenticated reads for R. prowazekii or B. quintana were found, the authors note this does not rule out their presence due to limitations of ancient DNA preservation.

Authors conclude that paratyphoid fever lineage Para C and louse-borne relapsing fever were present among Napoleonic soldiers during the 1812 retreat.

Historical testimony described widespread diarrhea and consumption of salted beets and brine along the route to Vilnius, consistent with a foodborne route for paratyphoid fever.

A scenario of fatigue, cold, and overlapping infections likely contributed to mortality.

Rémi Barbieri et al, Paratyphoid Fever and Relapsing Fever in 1812 Napoleon's Devastated Army, bioRxiv (2025). DOI: 10.1101/2025.07.12.664512

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 1:54pm

In their experiment, the researchers first squeezed their hydrocarbon samples to pressures greater than those within Earth's mantle using a diamond anvil cell. Then, they heated the samples to over 3,500 degrees Fahrenheit by hitting them repeatedly with X-ray pulses from the European XFEL.

The team recorded and analyzed how the X-rays scattered off the samples, which allowed them to resolve the structural transformations within. As expected, the recorded scattering patterns showed that the carbon atoms had formed a diamond structure. But the team also saw unexpected signals that were due to hydrogen atoms reacting with the gold foil to form gold hydride. Under the extreme conditions created in the study, the researchers found hydrogen to be in a dense, "superionic" state, where the hydrogen atoms flowed freely through the gold's rigid atomic lattice, increasing the conductivity of the gold hydride.

Mungo Frost et al, Synthesis of Gold Hydride at High Pressure and High Temperature, Angewandte Chemie International Edition (2025). DOI: 10.1002/anie.202505811

Part2

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 1:52pm

Scientists create gold hydride by combining gold and hydrogen under extreme conditions

An international research team formed solid binary gold hydride, a compound made exclusively of gold and hydrogen atoms.

The researchers were studying how long it takes hydrocarbons, compounds made of carbon and hydrogen, to form diamonds under extremely high pressure and heat.

In their experiments at the European XFEL (X-ray Free-Electron Laser) in Germany, the team studied the effect of those extreme conditions in hydrocarbon samples with an embedded gold foil, which was meant to absorb the X-rays and heat the weakly absorbing hydrocarbons. To their surprise, they not only saw the formation of diamonds, but also discovered the formation of gold hydride.

 Gold is typically chemically very  unreactive—that's why researchers use it as an X-ray absorber in the experiments.

These results suggest there's potentially a lot of new chemistry to be discovered at extreme conditions where the effects of temperature and pressure start competing with conventional chemistry, and you can form these exotic compounds.

The results, published in Angewandte Chemie International Edition, provide a glimpse of how the rules of chemistry change under extreme conditions like those found inside certain planets or hydrogen-fusing stars.

Part1

Comment by Dr. Krishna Kumari Challa on August 6, 2025 at 1:43pm

Eating earlier linked to long-term weight-loss success

 researchers report that eating earlier in the day blunts the weight gain ordinarily predicted by a high genetic score for obesity.

Meal timing has drawn attention for associated effects on metabolism, energy expenditure, and circadian alignment. Zeitgeber, a rhythmically occurring body phenomenon which acts as a cue in the regulation of the body's circadian rhythms, can also synchronize metabolic tissues such as the liver, pancreas, and adipose tissue.

Changes in food timing can alter zeitgeber, leading to a change in the molecular timing of circadian clock cues and, consequently, rhythms in metabolic function.

Peripheral oscillators in metabolic organs and tissues sensitive to food timing may become desynchronized from the central clock, which is highly sensitive to environmental light. It is hypothesized that such internal circadian misalignment may contribute to adverse cardiometabolic traits and obesity.

In the study, "Early meal timing attenuates high polygenic risk of obesity," published in Obesity, the team performed linear regression analyses to test whether meal timing interacts with a genome-wide polygenic score on BMI and long-term weight-loss maintenance.

Investigators calculated a polygenic risk score for BMI from 900,492 single-nucleotide polymorphisms and assessed the timing of meals. Midpoint of meal intake was calculated as the halfway time between a participant's first and last meals, weighted across weekdays and weekends. Linear regression models adjusted for age, sex, clinic site, and principal ancestry components.

Each hour of later midpoint corresponded to a 0.952 kg/m² higher baseline BMI and a 2.2% rise in body weight at 12 years (± 3 y) after treatment. Within the highest polygenic risk tertile, BMI climbed by about 2.21 kg/m² for every hour of meal delay. No association appeared in lower-risk groups.

The authors conclude that meal timing is associated with weight-loss maintenance and moderates genetic risk, suggesting that early eating could form part of personalized obesity interventions.

R De la Peña‐Armada et al, Early meal timing attenuates high polygenic risk of obesity, Obesity (2025). DOI: 10.1002/oby.24319

Divya Joshi et al, Timing Matters: Early Eating Mitigates Genetic Susceptibility for Obesity, Obesity (2025). DOI: 10.1002/oby.24350

Comment by Dr. Krishna Kumari Challa on August 5, 2025 at 1:09pm

How the brain constructs emotional experiences

Arousal—how alert or excited one feels—is a basic part of emotions, along with whether those emotions are positive or negative.

A recent study  published in Nature Communications uncovers a brain signature that reveals how emotional intensity is consciously experienced—and whether this experience is distinct from automatic bodily reactions.

Using a powerful combination of AI-driven modeling, advanced brain imaging, and close-to-real-life experimental paradigms, the team was able to uncover a brain signature that precisely measures emotional intensity (arousal) across diverse situations ranging from seeing a loved one to watching a horror movie. Notably, the team was able to disentangle the conscious emotional experience from automatic physiological responses such as sweating or heart racing.

The findings touch on a core debate that has fascinated philosophers and psychologists for more than 150 years, debating whether conscious feelings and bodily reactions can be separated. Such insights could drive the next generation of emotionally intelligent AI systems by indicating that conscious emotional experience can be disentangled from bodily aspects.

Beyond the theoretical implications, this discovery opens new avenues for:

• Developing and designing emotionally intelligent AI systems
• Advancing brain-computer interfaces and affective computing, and
• Designing more precise interventions for emotional disorders such as anxiety and depression.

In short, this research offers a better, more precise way to understand how our brains create emotional arousal, and it could help with future studies and applications in understanding emotions.

Ran Zhang et al, A neurofunctional signature of affective arousal generalizes across valence domains and distinguishes subjective experience from autonomic reactivity, Nature Communications (2025). DOI: 10.1038/s41467-025-61706-0

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Comment by Dr. Krishna Kumari Challa on August 5, 2025 at 11:58am

When the first repair attempt stalls at the separating strands (known as the "replication fork"), a set of proteins tasked with stabilizing the fork adds a phosphate—that's the label—to a "signaling" protein. The signal results in the release of the damaged chromosome from a physical tether, allowing it more freedom to move within the nucleus. This release also triggers the formation of microtubules—long polymerized "tracks" of proteins that lead right to the nuclear periphery. The damaged DNA is carried along those tracks to where repair can be completed.

Having uncovered how this backup mechanism for DNA repair works, the scientists who conducted this work points to a potential strategy for treating cancer: Cancer cells have to replicate their genomes really fast, and they may be relying heavily on these backup mechanisms of DNA repair to survive. If we can target DNA repair vulnerabilities, we might have a way to preferentially kill a cancer cell.
That is why we study everything in detail, to use the knowledge in controlling the situations and curing the diseases!

Isn't this more amazing?

Tyler M. Maclay et al, The DNA replication checkpoint targets the kinetochore to reposition DNA structure-induced replication damage to the nuclear periphery, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.116083

Part 2

Comment by Dr. Krishna Kumari Challa on August 5, 2025 at 11:55am

Cells have a second DNA repair toolbox for difficult cases

The human genome consists of 3 billion base pairs, and when a cell divides, it takes about seven hours to complete making a copy of its DNA. That's almost 120,000 base pairs per second. At that breakneck speed, one might expect errors to occur, and they do, at a rate of about two per second in every dividing cell. But cells have a "DNA repair kit" of enzymes that can correct those errors at a rate matching that at which they occur. 

That is amazing!

However, a bigger problem happens when there is a barrier to DNA replication, the process of copying the DNA. It can lead to a break in the chromosome, which will lead to loss of vital genetic information if not repaired. Gaps or breaks in DNA can be potentially harmful or fatal, should they lead to genetic diseases or cancer.

Researchers have  been examining cell DNA repair response to these critical events in yeast cells as an analog to human cells, and has discovered that the process is more elaborate and layered than previously thought.

In a recent study published in Cell Reports,  scientists looked at areas of the DNA that are particularly susceptible to breakage.

Those areas are where the sequence consists of long stretches of repeated triplets like CAGCAGCAG, or couplets like ATATATAT, which continue from just a few to hundreds of units long. When that occurs, the DNA may not always fold neatly into a long double helix, but may twist on itself to form hairpins and cruciform structures—like a tangled electric cord.

This is not a minor issue because repetitive DNA makes up about 10% of our genome, which is even greater than the portion that codes for protein.

When the strands become twisted, the repair proteins that scan the length of DNA can hit a snag and fail to carry out their task. That's when a second set of DNA repair proteins  comes into play.  Scientists are learning that there are backup mechanisms, and now it seems there is a place in the cell where the particularly difficult repairs go to get fixed.

That location is at the inner edge of the cell's nucleus, and a   recent paper by scientists describes how the damaged DNA gets there. The way the DNA gets to the periphery of the nucleus depends on the nature of the damage. For CAG repeats, to use an analogy, it's like adding a shipping label to the damaged goods and sending them out to the repair shop.

Part 1

Comment by Dr. Krishna Kumari Challa on August 5, 2025 at 11:08am

While this work might be groundbreaking, there are still some possible issues that need to be ironed out in future studies. For example, the experiment relies on post selection—where only certain photons are detected, possibly giving misleading results.

Another possible issue comes from a locality loophole due to the phase settings of the detectors not being separated properly. However, the study authors are aware of this study's limitations and are eager to find fixes to these issues and try again.

 Kai Wang et al, Violation of Bell inequality with unentangled photons, Science Advances (2025). DOI: 10.1126/sciadv.adr1794

Part 2

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