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Comment by Dr. Krishna Kumari Challa 16 hours ago

Tumor bacteria linked to immunotherapy resistance in head and neck cancer

Researchers have discovered that bacteria inside cancerous tumors may be key to understanding why immunotherapy works for some patients but not others.
Elevated bacterial levels within head and neck squamous cell carcinoma tumors suppress immune responses and contribute to resistance against immunotherapy. These bacteria attract neutrophils, which can inhibit the immune activity required for effective treatment. Reducing tumor bacteria with antibiotics may enhance immunotherapy efficacy, suggesting new avenues for patient selection and targeted interventions.

These studies shift the focus of immunotherapy resistance research beyond tumor genetics to unexpected factors like the tumor microbiome.

By identifying bacteria as a key barrier to treatment, we're opening the door to new strategies for patient selection and targeted antibiotic therapies, potentially improving outcomes for those who don't benefit from immunotherapy, the researchers say.

The research confirmed that patients with high tumor bacteria levels had poorer outcomes with immunotherapy compared to standard chemoradiotherapy.

Together, the two studies showed that elevated bacteria levels in tumors attract neutrophils, white blood cells that fight infection. While neutrophils are essential for combating bacterial infections, in cancer they can suppress the immune system needed for immunotherapy to work effectively.

These findings lay the foundation for future research on why bacteria are attracted to tumors and how to modify them to improve treatment.

1. Tumor ecosystem and microbiome features associated with efficacy and resistance to avelumab plus chemoradiotherapy in head and neck cancer, Nature Cancer (2025). DOI: 10.1038/s43018-025-01068-0

2. Nature Cancer (2025). www.nature.com/articles/s43018-025-01067-1

Comment by Dr. Krishna Kumari Challa 16 hours ago

Two 'survival modes' and why they matter
The researchers identified two archetypes of growth arrest that can both lead to persistence, but for very different reasons:

Regulated growth arrest: a protected dormant state. In this mode, bacteria intentionally slow down and enter a stable, defended condition. These cells are harder to kill because many antibiotics rely on bacterial growth to be effective.

Disrupted growth arrest: survival through breakdown. In the second mode, bacteria enter a dysregulated and disrupted state. This is not a planned shutdown, but a loss of normal cellular control. These bacteria show a broad impairment in membrane homeostasis, a core function needed to maintain the integrity of the cell. That weakness could become a key treatment target.
Antibiotic persistence plays a role in recurring infections across a wide range of settings, from chronic urinary tract infections to infections tied to medical implants. Yet despite intense research, scientists have struggled to agree on a single mechanism explaining why persister cells survive. Different experiments have produced conflicting results about what persisters look like and how they behave.

This study offers an explanation: researchers may have been observing different types of growth-arrested bacteria without recognizing they were distinct.

By separating persistence into two different physiological states, the findings suggest a future where treatments could be tailored, targeting dormant persisters one way, and disrupted persisters another.
How the researchers saw what others missed
The team combined mathematical modeling with several high-resolution experimental tools, including:

Transcriptomics, to measure how bacterial gene expression shifts under stress
Microcalorimetry, to track metabolic changes through tiny heat signals
Microfluidics, allowing scientists to observe single bacterial cells under controlled conditions
Together, these approaches revealed clear biological signatures distinguishing regulated growth arrest from disrupted growth arrest, along with the specific vulnerabilities of the disrupted state.

Adi Rotem et al, Differentiation between regulated and disrupted growth-arrests allows tailoring of effective treatments for antibiotic persistence, Science Advances (2026). DOI: 10.1126/sciadv.adt6577. www.science.org/doi/10.1126/sciadv.adt6577

Part 2

Comment by Dr. Krishna Kumari Challa 16 hours ago

Bacteria reveal second 'shutdown mode' for surviving antibiotic treatment
Bacteria can survive antibiotic treatment through two distinct growth-arrest states: a regulated, protective dormancy and a disrupted, dysregulated arrest marked by impaired membrane stability. This duality explains conflicting observations of antibiotic persistence and suggests that targeting each state differently could improve treatment effectiveness and reduce infection relapse.

A new study reveals that bacteria can survive antibiotic treatment through two fundamentally different "shutdown modes," not just the classic idea of dormancy. The paper is published in the journal Science Advances.

The researchers show that some cells enter a regulated, protective growth arrest, a controlled dormant state that shields them from antibiotics, while others survive in a disrupted, dysregulated growth arrest, a malfunctioning state marked by vulnerabilities, especially impaired cell membrane stability. This distinction is important because antibiotic persistence is a major cause of treatment failure and relapsing infections even when bacteria are not genetically resistant, and it has remained scientifically confusing for years, with studies reporting conflicting results.

By demonstrating that persistence can come from two distinct biological states, the work helps explain those contradictions and provides a practical path forward: different persister types may require different treatment strategies, making it possible to design more effective therapies that prevent infections from coming back.

For years, persistence has largely been blamed on bacteria that shut down and lie dormant, essentially going into a kind of sleep that protects them from antibiotics designed to target active growth. But new research reveals that this explanation tells only part of the story.

The study shows that high survival under antibiotics can originate from two fundamentally different growth-arrest states, and they are not just variations of the same "sleeping" behavior. One is a controlled, regulated shutdown, the classic dormancy model. The other is something entirely different: a disrupted, dysregulated arrest, where bacteria survive not by protective calm but by entering a malfunctioning state with distinct vulnerabilities.

Part 1

Comment by Dr. Krishna Kumari Challa 16 hours ago

Two white-blooded fish, two paths: Icefish and noodlefish independently lose red blood cell function

Both Antarctic icefish and Asian noodlefish independently evolved to lack hemoglobin and red blood cells, resulting in white blood. Icefish survive in cold, oxygen-rich waters by dissolving oxygen directly in their blood, while noodlefish, living in warmer waters, lost myoglobin and have nonfunctional hemoglobin genes, likely aided by their short, juvenile-like life span. These findings highlight distinct evolutionary paths to similar physiological outcomes.

 Yu-Long Li et al, Independent evolutionary deterioration of the oxygen-transport system in Asian noodlefishes and Antarctic icefishes, Current Biology (2025). DOI: 10.1016/j.cub.2025.05.050

Comment by Dr. Krishna Kumari Challa 16 hours ago

Evidence of upright walking found in 7-million-year-old Sahelanthropus fossils

Analysis of Sahelanthropus tchadensis fossils using 3D methods identified features unique to bipedal hominins, including a femoral tubercle, femoral antetorsion, and gluteal muscle attachments. These findings indicate that this seven-million-year-old species was adapted for upright walking, making it the earliest known bipedal hominin.

The analysis revealed three features that point to bipedalism in Sahelanthropus:

The presence of a femoral tubercle, which provides attachment for the iliofemoral ligament linking the pelvis to the femur and has so far been identified only in hominins

A natural twist, specifically within the range of hominins, in the femur—or femoral antetorsion—that helps legs to point forward, thereby aiding walking.

The presence, drawn from the 3D analysis, of gluteal, or butt, muscles similar to those in early hominins that keep hips stable and aid in standing, walking, and running.

Scott Williams, Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis, Science Advances (2026). DOI: 10.1126/sciadv.adv0130. www.science.org/doi/10.1126/sciadv.adv0130

Comment by Dr. Krishna Kumari Challa 16 hours ago

Ancient African bedrock reveals the violent beginnings of life on our blue planet

Ancient bedrock from the Makhonjwa Mountains reveals that early Earth featured extensive oceans, intense volcanic activity, and a hostile atmosphere rich in methane and CO2 but lacking oxygen. Life began as anaerobic microbes near undersea vents, thriving despite frequent volcanic eruptions, earthquakes, and asteroid impacts. Plate tectonics and a stable climate enabled Earth to remain habitable and blue.

The Oldest Rocks on Earth | Columbia University Press

Ancient African bedrock reveals the violent beginnings of life on o...

Comment by Dr. Krishna Kumari Challa yesterday

Traffic Has a Curious Effect on The Atmosphere's Electric Field, Study Shows

Detailed measurements collected in metropolitan Tel Aviv, Israel, have revealed how the ebb and flow of traffic throughout the week affects the electric field generated by Earth's atmosphere.

A number of specific pollutants were tracked, including gases and particles from car exhaust and tire wear, and additional compounds formed in chemical reactions with gases in the atmosphere.

The atmospheric electric field is the result of natural differences in charge between the surface and upper atmosphere, powered largely by the swirl of currents that form in thunderstorms.

A number of factors influence this planetary circuit, including fluctuations in local weather and air pollution. 

The data showed that traffic pollution in Tel Aviv has an immediate impact on the atmospheric electric field in the region, with both NOx gases and vehicle congestion peaking at the same times (the rush hours at the start and end of the working day).

There was also an association between PM2.5 particles and the electric field, though this was delayed by around two-and-a-half hours. The researchers put this down to different particle size, chemical composition, and lifetime in the atmosphere.

The team reports a noticeable weekend effect as well, with significant drops in traffic pollution corresponding with a weakening of the electrical field. That's further confirmation that the two are indeed linked.

What they observed is a direct physical link between emission peaks and electrical variability.

Nitrogen oxides reduce atmospheric conductivity very quickly, so the electric field responds almost instantaneously during traffic rush hours.

The reason behind the effect is ions: the charged particles in the air. Pollutants can capture these ions, reducing the conductivity of the atmospheric electric field, which then triggers a compensatory effect where the electric field gets stronger.

These changes aren't dangerous, and nor is the electric field itself .

Effects of urban air pollution on the fair-weather electric field i...

Comment by Dr. Krishna Kumari Challa on Wednesday

Clouds are vital to life—but many are becoming wispy ghosts. Here's how to see the changes above us
Cloud cover, especially highly reflective clouds near the equator, is steadily declining by 1.5–3% per decade, reducing Earth's ability to reflect solar radiation and increasing heat retention. This shift alters rainfall patterns and climate stability, with the loss often unnoticed. Clouds play a crucial role in moderating temperature and sustaining life, making their decline a significant concern.

--

skies that feel hollowed out, clouds that look like they have lost their conviction. I think of them as ghost clouds. Not quite absent, but not fully there. These wispy formations drift unmoored from the systems that once gave them coherence. Too thin to reflect sunlight, too fragmented to produce rain, too sluggish to stir up wind, they give the illusion of a cloud without its function.

Clouds are vital to life – but many are becoming wispy ghosts. Here...

Comment by Dr. Krishna Kumari Challa on Tuesday

'Don't use them': Tanning beds triple skin cancer risk, study finds

Tanning bed use is associated with nearly a threefold increase in melanoma risk, with users developing more DNA mutations in skin cells, particularly melanocytes. Melanomas in tanning bed users often appear on body areas usually shielded from sunlight. Over 80% of common melanomas are linked to ultraviolet radiation, including that from tanning beds.

Pedram Gerami et al, Molecular effects of indoor tanning, Science Advances (2025). DOI: 10.1126/sciadv.ady4878. www.science.org/doi/10.1126/sciadv.ady4878

Comment by Dr. Krishna Kumari Challa on Tuesday

New sprayable powder forms instant gel barrier to stop severe bleeding in seconds

A sprayable powder hemostatic agent rapidly forms a hydrogel barrier within one second upon contact with blood, effectively stopping severe bleeding, including from deep or irregular wounds. Composed of biocompatible natural materials, it demonstrates high absorption (725%), strong adhesion (>40 kPa), low hemolysis (<3%), high cell viability (>99%), and antibacterial properties (99.9%).

Youngju Son et al, An Ionic Gelation Powder for Ultrafast Hemostasis and Accelerated Wound Healing, Advanced Functional Materials (2025). DOI: 10.1002/adfm.202523910

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