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Comment by Dr. Krishna Kumari Challa 16 hours ago

Women with severe burn injuries are more likely than men to develop blood poisoning

The skin forms a natural barrier that prevents bacteria entering the body. Severe burns stop this protective function from working properly, and germs can enter the blood more easily through the wounds. If the airways have suffered thermal or chemical injury through the inhalation of hot and toxic substances, they are also a gateway for infection.
Bacteria can multiply in the blood and spread throughout the body. In the worst case, this can cause blood poisoning—also known as sepsis—which can lead to multiple organ failure. This is a common cause of death in people with burn injuries. A new study has identified for the first time which patients are affected by such infections. The study was carried out before the disaster in Crans-Montana, but it can now help to better understand the physiological processes in critically ill burn patients.

The study focused on sex-specific differences. It analyzed data from 269 patients with severe burn injuries who were treated at the Center for Severe Burn Injuries at the University Hospital Zurich between 2017 and 2021. The insights, published in Burns, should help to prevent sepsis in patients with severe burn injuries or get it under control at an early stage.

Women with severe burn injuries are nearly twice as likely as men to develop bacteremia, which can progress to sepsis. This increased risk is not due to different bacterial species but may relate to altered immune or hormonal responses following burns. Understanding these mechanisms could improve prevention and management of sepsis in burn patients.
Women's immune systems often seem better able to cope with pathogens, and a number of studies have observed a stronger immune response.
In burn victims, however, it seems that this is not necessarily the case. The researchers are not yet able to answer the question of why the women with severe burn injuries in this cohort were much more likely to develop bacteremia.
One explanation that can be ruled out, however, is the presence of different pathogens, as predominantly the same bacteria were identified in the blood of male and female patients. These are species that colonize the skin and mucous membranes as part of the natural microbiome. They are usually harmless but can become dangerous if they enter the bloodstream in large quantities.
Sex hormones have an effect on human immune cells, which also fight infections. Female sex hormones such as estrogen are actually associated with a better response. But it is possible that burn injuries alter hormone metabolism, which then weakens the immune response, say the researchers.
While patients are usually given antibiotics early to fight the bacteria, the damaged barrier means that new infections keep occurring. Resistant bacteria can also quickly develop, for which very few effective antibiotics are available.

Nicole J.M. Schweizer et al, Impact of sex on the development of bacteremia in critically ill burn patients: A retrospective cohort study, Burns (2026). DOI: 10.1016/j.burns.2025.107845

Comment by Dr. Krishna Kumari Challa 16 hours ago

Why corals bleach: Neutrons show algae photosynthesis breaking down

Rising sea temperatures are causing coral reefs around the world to bleach. For the first time, a research team has investigated the biological processes behind coral bleaching directly in living corals. With the help of neutrons, they were able to visualize structural changes during the bleaching process.
Rising sea temperatures disrupt photosynthesis in coral-associated algae by altering the structure of their thylakoid membranes. Using small-angle neutron scattering, researchers directly observed these structural changes in living corals, linking membrane stress to the breakdown of symbiosis and subsequent coral bleaching. Persistent bleaching can lead to coral death.

Robert W. Corkery et al, In hospite and ex hospite architecture of photosynthetic thylakoid membranes in Symbiodinium spp. using small-angle neutron scattering, Journal of Applied Crystallography (2025). DOI: 10.1107/s1600576725007332

Comment by Dr. Krishna Kumari Challa 16 hours ago

How a one‑eyed creature gave rise to our modern eyes

There is a tiny cyclops among your oldest ancestors, and humans share these remarkable ancestral roots with all other vertebrates. Researchers have found that all vertebrates evolved from a distant ancestor that had a single eye located at the top of its head. The study, published in Current Biology, also reveals that the remnants of this so-called median eye have today become the pineal gland in our brains.

This cyclops-like creature, which is our very distant relative, existed almost 600 million years ago. It was a small, worm-like organism that had adopted a sedentary lifestyle and fed by filtering plankton from seawater. Previously, this creature had some form of paired eyes, like most other animals.

We don't know whether the paired eyes in our branch of the evolutionary tree were just light-sensitive cells or simple image-forming eyes. We only know that the organism later lost them.
The increasingly calm lifestyle meant that the worm-like creature no longer needed paired eyes, and therefore that function was lost over the course of evolution. However, the animal kept a group of light-sensitive cells in the middle of its head. These cells developed into a small, primitive median eye that could keep track of night and day, and sense what was up and down.
Over the following millions of years, our distant ancestor once again began to live an active, swimming life, increasing the need for paired eyes. From parts of the small median eye, new image-forming eyes in pairs developed, the researchers conclude in the study.
Now we finally understand why the eyes of vertebrates differ so radically from the eyes of all other animal groups, such as insects and squid. The film of our eyes—the retina—developed from the brain, whereas the eyes of insects and squid originate in the skin on the sides of the head.
In other words, vertebrate eyes constitute a more modern model that evolved thanks to this peculiar detour via a cyclops' sedentary life. The conclusion that our modern eyes evolved through this specific evolutionary path, and not via some other ancient animal, is based on the researchers' extensive analysis of light-sensitive cells in all animal groups, as well as the physiology and placement of these cells in the body.
All vertebrates evolved from an ancestor with a single median eye atop its head, which later became the pineal gland in the brain. This median eye, originally used for light detection, was retained after the loss of paired eyes and eventually gave rise to the paired, image-forming eyes of modern vertebrates. The retina’s brain origin distinguishes vertebrate eyes from those of other animals.

George Kafetzis et al, Evolution of the vertebrate retina by repurposing of a composite ancestral median eye, Current Biology (2026). DOI: 10.1016/j.cub.2025.12.028

Comment by Dr. Krishna Kumari Challa 17 hours ago

Women show greater tau buildup and faster cognitive decline than men in Alzheimer's

Tau proteins act like the brain's maintenance crew, helping maintain the structure and proper function of brain cells. In neurodegenerative diseases such as Alzheimer's, the tau proteins can form tangles that disrupt normal cell function. A recent study published in JAMA Neurology found that women show significantly higher levels of tau protein accumulation and experience faster cognitive decline than men.

A multinational team of researchers analyzed data from 1,200 participants across five major studies—one clinical trial and four observational studies—to better understand how Alzheimer's disease progresses differently in men and women. Their focus was on a trigger protein called amyloid-beta that leads to tau abnormalities.

The data indicated that when amyloid levels were high in both women and men, women had significantly higher levels of p-tau217 than men, suggesting that the tau protein clumps together more quickly in a woman's brain, making them more susceptible to the very early stages of the disease process. On the other hand, when the p-tau217 levels are lower, women seem to do better at cognitive tests than men.

Gillian T. Coughlan et al, Sex Differences in P-Tau217, Tau Aggregation, and Cognitive Decline, JAMA Neurology (2026). DOI: 10.1001/jamaneurol.2025.5670

Comment by Dr. Krishna Kumari Challa 17 hours ago

Dry eye often precedes autoimmune disease diagnosis, new study finds

Frequent dry eyes may signal more than simple irritation and could be an early warning sign of an autoimmune disease. This symptom has long been associated with Sjögren's Disease, a chronic autoimmune condition in which the immune system mistakenly attacks the tear ducts and salivary glands, causing inflammation that leads to dry eyes and dry mouth. Now, a study of 67,264 patients in Taiwan with autoimmune diseases found that dry eye disease (DED) preceded the autoimmune diagnosis by about three years.

Predictably, in Sjögren's Disease, the prevalence of diagnosis following the occurrence of DED exceeded 80%. Across nine other autoimmune conditions, rates consistently exceeded 20%, with rheumatoid arthritis ranking second highest at 39.3%, while Crohn's disease recorded the lowest rate at 23.0%.

DED provides a vital window of opportunity for doctors to perform earlier clinical evaluations for underlying autoimmune issues and plan effective treatment plans to deal with the symptoms. The findings are published in JAMA Network Open.

Greater awareness of DED as a potential early warning sign could encourage more people to seek evaluation, leading to earlier detection of underlying autoimmune disease when present, and if not, proceed with a general DED treatment plan.

Nan-Ni Chen et al, Epidemiology of Dry Eye in Patients With Autoimmune Disease, JAMA Network Open (2026). DOI: 10.1001/jamanetworkopen.2025.60275

Comment by Dr. Krishna Kumari Challa 17 hours ago

Urine tests confirm alcohol consumption in wild African chimpanzees

 If you want to measure the alcohol intake of chimps in a Ugandan rain forest, where a breath-analyzer is impractical, collecting urine for analysis is your only choice.

In 2025, researchers documented that the fruits chimps eat in the wild contain enough alcohol from fermentation to provide around 14 grams per day—the equivalent of two standard drinks. But the proof is in the urine.

So they collected the urine of Chimps to test. 

Their new results, published in the journal Biology Letters, show that the urine of most chimps sampled contains a metabolic by -product of alcohol, ethyl glucuronide, that proves they ingest significant quantities of ethanol in their diet—likely from those fermenting fruits.

Of the 20 urine samples from 19 different chimps (the Western chimpanzee, Pan troglodytes), 17 tested positive on commercial strips sensitive to 300 nanograms per milliliter (ng/ml) or more ethanol. Eleven samples were tested with strips sensitive to 500 ng/ml or more; 10 were positive (making a total of four out of 20 below the 500 ng/ml cutoff).

In humans, 500 ng/ml is a level expected after light drinking—one to two standard drinks—within the previous 24 hours. Similar levels would be expected in a chimpanzee that had spent the morning scarfing down slightly fermented fruit.

This confirms that the drunken monkey hypothesis—that there's enough alcohol in the environment for animals to experience alcohol in a way analogous to humans.

Urinary concentrations of a direct ethanol metabolite indicate substantial ingestion of fermenting fruit by chimpanzees, Biology Letters (2026). DOI: 10.1098/rsbl.2025.0740

Comment by Dr. Krishna Kumari Challa yesterday

Why our immune system remembers vaccinations for decades
Long-lived immunological memory after vaccination is maintained by memory T cells that enter an energy-saving, low-metabolic state early after activation. This metabolic restraint enables them to persist for decades and rapidly respond to future infections. The principle applies broadly, including to COVID-19 vaccination, and may inform improved vaccine design.

Sina Frischholz et al, Metabolic quiescence of naive-like memory T cells precedes and maintains antigen-specific T cell memory, Nature Immunology (2026). DOI: 10.1038/s41590-026-02421-w

Comment by Dr. Krishna Kumari Challa yesterday

In simple terms, quorum sensing involves chemical signals released by bacteria. Only when many bacteria have grown in a tumor is the signal strong enough to turn on the oxygen-resistant gene, ensuring it doesn't happen too soon.

In a 2023 study, researchers demonstrated that Clostridium sporogenes can be modified to tolerate oxygen. Now, in a follow-up study published in the journal ACS Synthetic Biology, they tested their quorum sensing system by making bacteria produce a green fluorescent protein.
Researchers now plan to combine the oxygen-resistant gene and the quorum-sensing timing mechanism in one bacterium and test it on a tumor in pre-clinical trials.

Sara Sadr et al, Construction and Functional Characterization of a Heterologous Quorum Sensing Circuit in Clostridium sporogenes, ACS Synthetic Biology (2025). DOI: 10.1021/acssynbio.5c00628

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Engineered bacteria can consume tumors from the inside out

A research team is developing a novel tool to treat cancer by engineering hungry bacteria to literally eat tumors from the inside out. "Bacteria spores enter the tumor, finding an environment where there are lots of nutrients and no oxygen, which this organism prefers, and so it starts eating those nutrients and growing in size.
Engineered Clostridium sporogenes bacteria have been modified to survive in low-oxygen tumor environments and selectively activate oxygen resistance via quorum sensing. This approach enables the bacteria to colonize and degrade tumors from within while minimizing risk to healthy, oxygen-rich tissues. Pre-clinical trials are planned to test this targeted cancer therapy.

Key to the approach is a bacterium called Clostridium sporogenes, which is commonly found in soil and can only grow in environments with absolutely no oxygen. The core of a solid, cancerous tumor is comprised of dead cells and is oxygen-free, making it an ideal breeding ground for the bacterium to multiply.
But there is a biological catch: when the cancer-eating organisms reach the outer edges of tumors, they are exposed to low levels of oxygen and die without completing their mission to fully destroy them.

To solve that problem, the researchers first added a gene to the organism from a related bacterium that can better tolerate oxygen, enabling it to live longer near the outside of a targeted tumor.

They then found a way to activate the oxygen-resistant gene at just the right time—critical to preventing bacteria from inadvertently growing in oxygen-rich places such as the bloodstream—by leveraging a phenomenon known as quorum sensing.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

AI provides a more precise time of death post-mortem

Artificial intelligence can be used to provide a more precise time of death, which could be crucial in murder investigations. The method was developed by researchers.
Artificial intelligence analyzing blood metabolites enables more precise estimation of time since death, improving accuracy to about one day even up to 13 days post-mortem. This method outperforms traditional forensic techniques and requires relatively modest data sets, making it applicable in various laboratories. Further refinement aims to enhance precision and determine the time of day of death.
When the body dies, a number of biological processes set in. Organs and tissues begin to break down, leading to changes in small molecules in the blood called metabolites. They are broken down in a predictable way that correlates with how much time has elapsed since the time of death.
This enables us to assess the actual time of death of an individual, which is very important in forensic investigations, but also to the work of the police. For example, they need to spend their resources on the right witnesses in the right period of time in the deceased person's life.
Limits of today's forensic methods
The methods currently used to determine the time of death, also known as the post-mortem interval, include body temperature, rigor mortis, and the amount of potassium in the vitreous of the eye. However, these methods yield less accurate results when a few days have passed since the time of death.

The method now developed by researchers instead uses artificial intelligence to analyze the metabolites in blood samples collected at autopsy.
Blood samples from more than 45,000 autopsies have been collected by RMV over a period of almost 10 years, resulting in a world-unique database. The samples are used to find various chemical substances such as drugs, pharmaceuticals, or toxins. But body metabolites can also be found in the blood samples. Of these 45,000 samples, 4,876 with known post-mortem interval were used to train the AI model.
The researchers showed that their new model could predict the time from death to autopsy with a precision of about one day, even for those deceased for up to 13 days. A clear improvement on current methods.
Many external factors affect body decomposition but the signal from the body's metabolites was so strong when it comes to predicting the post-mortem interval.

So the researchers' next step is to produce a data set with more precise information about the time of death, and then train models that will provide more reliable estimates of the post-mortal interval as well as be able to determine during which part of the day a death occurred.
Forensic assessments often involve puzzle-like detective work. This new tool gives us better opportunities to assess how long someone has been deceased, even when a long time has passed since their death, which is of great importance, especially in more complex cases.

Rasmus Magnusson et al, The human metabolome and machine learning improves predictions of the post-mortem interval, Nature Communications (2026). DOI: 10.1038/s41467-026-69158-w

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