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Comment by Dr. Krishna Kumari Challa 7 hours ago

Jellyfish don’t need brains to sleep!

Jellyfish sleep like humans — even though they don’t have brains

Studying ancient sea creatures’ snoozing habits could shed light on the origins of sleep.

Jellyfish and sea anemones have neurons, but no brains — and yet they still seem to sleep in ways strikingly similar to humans. The findings bolster a theory that sleep evolved — before centralized nervous systems — to repair DNA damage that builds up in individual nerve cells while animals are awake. Neurons are very precious. They don’t divide, so you need to keep them intact.

The findings bolster a theory that sleep evolved, at least in part, to protect the DNA in individual nerve cells, helping to repair damage that builds up while animals are awake.

Sleep is a risky state for animals. It leaves them vulnerable to predators and environmental hazards, and it cuts into time that could otherwise be spent foraging, mating or caring for offspring. Scientists broadly agree that sleep must serve a fundamental biological function, because evolution has preserved it across all animals with nervous systems studied so far.

These results suggest that DNA damage and cellular stress in simple nerve nets may have driven the evolution of sleep.

https://www.nature.com/articles/s41467-025-67400-5

https://www.nature.com/articles/d41586-026-00044-7?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa 7 hours ago

Diet may influence tinnitus risk in women

Diet may influence the risk of women developing tinnitus, according to a study published online Dec. 17 in the American Journal of Epidemiology.
Higher fruit intake is associated with reduced risk of developing persistent tinnitus in women, while greater consumption of whole grains, legumes, and sugar-sweetened beverages is linked to increased risk. Overall healthy diet patterns did not consistently affect tinnitus risk. These associations remained after accounting for lifetime noise exposure.

This study provides compelling evidence that dietary intake can influence the development of persistent tinnitus.

Sharon G Curhan et al, Longitudinal Study of Dietary Intake and Risk of Persistent Tinnitus in Two Large Independent Cohorts of Women, American Journal of Epidemiology (2025). DOI: 10.1093/aje/kwaf277

Comment by Dr. Krishna Kumari Challa 7 hours ago

Vitamin C may help protect fertility from a harmful environmental chemical

Exposure to potassium perchlorate impairs sperm production and damages testes in a fish model, indicating potential reproductive risks. Co-administration of vitamin C reduces this damage and improves fertility, likely by counteracting oxidative stress. These results suggest vitamin C may help protect reproductive health from certain environmental contaminants.

Sourav Chakraborty et al, Vitamin C Mitigates Potassium Perchlorate Exposure-Induced Disruption of Spermatogenesis in Medaka, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c09514

Comment by Dr. Krishna Kumari Challa 7 hours ago

Orange pigments in birds and human redheads prevent cellular damage, study shows

A pigment that makes feathers and hair orange helps prevent cellular damage by removing excess cysteine from cells. Pheomelanin is an orange-to-red pigment that is built with the amino acid cysteine and found in human red hair and fair skin, as well as in bird feathers. Previous research has shown that pheomelanin is associated with increased melanoma risk, raising questions about why evolution has maintained genetic variants that promote pheomelanin production.

Published in PNAS Nexus, researchers studied 65 adult zebra finches divided into treatment and control groups. In the treatment group, male zebra finches received dietary cysteine and ML349, a drug that blocks pheomelanin synthesis.

Male birds treated with both cysteine and ML349 showed increased oxidative damage in blood plasma compared to males receiving only cysteine, when the authors controlled for overall expression of the regulator of antioxidants by melanocytes. Female birds, which do not produce pheomelanin, tended to show increased oxidative damage when treated with cysteine alone as compared to female controls.

According to the authors, pheomelanin synthesis helps maintain cysteine homeostasis by converting excess cysteine into inert pigment, which may explain why pheomelanin-promoting genetic variants persist despite being associated with increased melanoma risk.

 Ismael Galván et al, MC1R depalmitoylation inhibition reveals a physiological role for pheomelanin, PNAS Nexus (2026). DOI: 10.1093/pnasnexus/pgaf391

Comment by Dr. Krishna Kumari Challa 7 hours ago

In nature we usually see that one process is favoured over many. Why is this?

It's true, but in biological systems, catalysis often intervenes—the action of facilitating molecules, enzymes—which accelerate reactions and make them less costly, achieving the same effect as having multiple pathways in parallel. This evolutionary choice happens because maintaining many pathways can have other drawbacks, such as producing many potentially toxic molecules.

 Thermodynamic ranking of pathways in reaction networks, Journal of Statistical Mechanics Theory and Experiment (2025). DOI: 10.1088/1742-5468/ae22eb.

Part 3

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Comment by Dr. Krishna Kumari Challa 7 hours ago

Yet from the viewpoint of classical mechanics, compartmentalization and reaction selection—the "constraints" imposed at a system's boundaries—should have no cost at all, as they are treated as fixed external conditions that do not contribute to entropy production.
Researchers now developed a method to calculate these overlooked costs to rank the pathways. This allows researchers to assess their biological efficiency—valuable information for evolutionary studies exploring how life emerged on our planet.
devised a general method to estimate the thermodynamic costs of metabolic processes systematically. In their framework, the cell is imagined as a system crossed by a constant flow, where, for instance, one molecule (a nutrient) enters and another (a product or waste) exits.

Given the underlying chemistry, one can generate all chemically possible pathways that convert the input into the output. Each pathway has its own "thermodynamic cost." Instead of calculating energy in the classical sense, the method estimates how improbable it would be—in a world driven solely by spontaneous chemistry—to see the network (the set of molecules and reactions that convert input to output) behave in exactly that way.

This improbability has two components. The first is the maintenance cost, meaning how unlikely it is to sustain a constant flow through a certain pathway. The second is the restriction cost, which measures how unlikely it is to block all the alternative reactions in the network while keeping only the pathway of interest active.

The calculated improbability represents the cost of that process, which can then be used to classify metabolic pathways according to how "expensive" it is for the cell to keep one pathway active and silence the others.
Part 2

Comment by Dr. Krishna Kumari Challa 7 hours ago

The (metabolic) 'cost of life': New method quantifies hidden energy costs of maintaining metabolic pathways
A new thermodynamic framework quantifies the hidden energetic costs required to maintain specific metabolic pathways and suppress alternatives, beyond direct metabolic energy use. This method ranks pathways by their maintenance and restriction costs, revealing that nature often selects the least dissipative routes, providing insights into the evolution and selection of metabolic processes.

There are "costs of life" that mechanical physics cannot calculate. A clear example is the energy required to keep specific biochemical processes active—such as those that make up photosynthesis, although the examples are countless—while preventing alternative processes from occurring.

In mechanics, no displacement implies zero work, and, put simply, there is no energetic cost for keeping things from happening. Yet careful stochastic thermodynamic calculations show that these costs do exist—and they are often quite significant.

A paper published in the Journal of Statistical Mechanics: Theory and Experiment (JSTAT) proposes a way to calculate these costs from a thermodynamic perspective and thus to offer a new tool for understanding the selection and evolution of metabolic pathways at the root of life.

When, in an ancient ocean, a handful of organic molecules formed an external boundary—the first cell membrane—a sharp distinction between an inside and an outside appeared for the first time.

From that moment on, that primordial system had to invest energy to maintain this compartmentalization and to select, among the many chemical reactions that could occur, only a few metabolic pathways capable of exploiting valuable substances taken from the "outside" and transforming them into new products. Life was born together with this effort of compartmentalization and choice.

Metabolic processes have a direct energetic cost, but they also require an "extra cost" to keep steering chemical flows into a preferred pathway rather than letting them disperse into all physically possible alternatives.

Part 1

Comment by Dr. Krishna Kumari Challa 8 hours ago

Cohort groups included 13,957 children conceived via assisted reproductive technology and 55,828 children conceived naturally after 1:4 matching by maternal age, neonatal sex, and birth month.

Asthma, allergic rhinitis, and atopic dermatitis were analyzed and reported individually, allowing a child to receive one, two, or all three diagnoses during follow-up. Mean follow-up for asthma measured 7.99 years in the assisted reproductive technology group and 8.41 years in the control group, with allergic rhinitis at 5.79 and 6.34 years, and atopic dermatitis at 7.34 and 7.62 years.
Intracytoplasmic sperm injection use showed no statistically significant differences in risk estimates across the three outcomes. Adjusted hazard ratios measured 1.04 for asthma, 0.99 for allergic rhinitis, and 1.04 for atopic dermatitis.

Fresh embryo transfer carried a higher allergic rhinitis risk than frozen embryo transfer, with an adjusted hazard ratio of 1.12. Asthma showed no statistically significant difference between fresh and frozen embryo transfer, with an adjusted hazard ratio of 0.96, and atopic dermatitis showed no statistically significant difference, with an adjusted hazard ratio of 1.01.

Interaction testing showed no statistically significant interaction between intracytoplasmic sperm injection and embryo type for asthma, allergic rhinitis, or atopic dermatitis.
Researchers conclude that children conceived via assisted reproductive technology had a higher risk of developing asthma, allergic rhinitis, or atopic dermatitis than children conceived naturally. Findings supported an association between assisted reproductive technology conception and later atopic disease development across the outcomes evaluated.

Yao-Chi Hsieh et al, Atopic Disease Development in Offspring Conceived via Assisted Reproductive Technology, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.51690

Part 2

Comment by Dr. Krishna Kumari Challa 8 hours ago

Assisted reproductive technology associated with higher risk of childhood atopic diseases

Researchers  report higher risks of atopic disease among children conceived via assisted reproductive technology compared to those conceived naturally.

Assisted reproductive technology use has increased, with estimates placing assisted reproductive technology at 1% to 4% of births, especially in high-income societies, alongside wider use of embryo transfer.

Atopic disease covers three conditions; asthma, allergic rhinitis, and atopic dermatitis. Atopic diseases are believed to be influenced by genetic factors and environmental triggers, with developmental origins of health and disease theory proposing that fetal-stage factors can program changes in organ and tissue structure and function.

In the study, "Atopic Disease Development in Offspring Conceived via Assisted Reproductive Technology," published in JAMA Network Open, researchers conducted a retrospective, population-based cohort analysis to investigate whether conception via assisted reproductive technology was associated with atopic disease development in offspring.

Data came from a pool of 23.5 million people in Taiwan through Taiwan's National Health Insurance Research Database, Assisted Reproduction Database, and the Maternal and Child Health Database.

Assisted reproductive technology included procedures such as in vitro fertilization and embryo transfer, intracytoplasmic sperm injection, gamete intrafallopian transfer, zygote intrafallopian transfer, and tubal embryo transfer.

Part 1

Comment by Dr. Krishna Kumari Challa on Saturday

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

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