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Comment by Dr. Krishna Kumari Challa on September 20, 2025 at 9:19am

Think before you ink: Uncovering the hidden risks in tattoo inks

New research suggests that what's in the ink may pose greater risks than the size and design of the tattoo.

A new study has revealed that the ingredients listed on tattoo ink labels often don't match what's actually inside the bottle. Researchers warn that this comes with risk because there are currently few regulations, laws and safety criteria for tattoo and permanent cosmetic formulations.

The findings, published this month as the cover story in the Journal of Environmental Health, raise fresh concerns about the safety and regulation of tattoo inks.

Using a combination of advanced analytical techniques, researchers found discrepancies between labeled and actual ingredients in a range of commercially available yellow tattoo inks.

The results showed not only discrepancies with label claims, but also the presence of unlisted elements such as aluminum, sodium and silicon.

Batool A. Aljubran et al, Decoding Tattoo Inks: Multiple Analysis Techniques Reveal Discrepancies in Ingredient Composition and Elemental Content When Compared Against Label Claims, Journal of Environmental Health (2025). DOI: 10.70387/001c.143999

Comment by Dr. Krishna Kumari Challa on September 20, 2025 at 9:13am

Sugary drinks may increase risk of metastasis in advanced colorectal cancer

A new study by researchers shows that the glucose-fructose mix found in sugary drinks directly fuels metastasis in preclinical models of advanced colorectal cancer. The study was published today in Nature Metabolism.

The researchers studied how sugary drinks may affect late-stage colorectal cancer. Using laboratory cancer models, they compared the effects of the glucose-fructose mix found in most sugary drinks with those of glucose or fructose alone. Only the sugar mix made cancer cells more mobile, leading to faster spread to the liver—the most common site of colorectal cancer metastasis.

The sugar mix activated an enzyme called sorbitol dehydrogenase (SORD), which boosts glucose metabolism and triggers the cholesterol pathway, ultimately driving metastasis. This is the same pathway targeted by statins, common heart drugs that inhibit cholesterol production. Blocking SORD slowed metastasis, even with the sugar mix present. These findings suggest that targeting SORD could also offer an opportunity to block metastasis.

These  findings highlight that daily diet matters not only for cancer risk but also for how the disease progresses once it has developed.

Fructose and glucose from sugary drinks enhance colorectal cancer metastasis via SORD, Nature Metabolism (2025). DOI: 10.1038/s42255-025-01368-w. www.nature.com/articles/s42255-025-01368-w

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 12:04pm

New cancer clue discovered in our saliva

Scientists have discovered a brand-new type of DNA element swimming in our saliva.

The giant loops of genetic information – named ‘inocles’ – are linked to oral health, the immune system, and cancer risk.

Those with head and neck cancers show far fewer of these DNA elements in their mouths.

Inocles are found in roughly 75 percent of the population. Like little survival kits, their presence might help certain oral bacteria during stressful times, possibly altering the microbiome in our mouths.

How that impacts tumor growth is a mystery to solve. Right now, 95 percent of the genes in inocles remain elusive. https://www.nature.com/articles/s41467-025-62406-5

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 10:22am

India health alert after 'brain-eating' amoeba rise

India has issued a health alert after infections and deaths caused by a rare water-borne "brain-eating" amoeba doubled compared to last year in the southern state of Kerala.

Officials were "conducting tests on a large scale across the state to detect and treat cases."

Officials reported 19 deaths and 72 infections of the Naegleria fowleri amoeba this year, including nine deaths and 24 cases in September alone.

Last year, the amoeba killed nine people out of 36 reported cases.

The US Centers for Disease Control and Prevention (CDC) says it is often called a "brain-eating amoeba" because it can "infect the brain and destroy brain tissue."

If the amoeba reaches the brain, it can cause an infection that kills over 95% of those affected.

Infections are "very rare but nearly always fatal," the CDC notes.

The amoeba lives in warm lakes and rivers and is contracted by contaminated water entering the nose. It does not spread from person to person.

The World Health Organization says that symptoms include headache, fever and vomiting, which rapidly progresses to "seizures, altered mental status, hallucinations, and coma."

Source: News Agencies

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 10:12am

Age 70 identified as cutoff for chemotherapy benefit in colorectal cancer

Colorectal cancer remains a leading cause of cancer death, with incidence rising among older adults. One of the most pressing clinical questions has been whether elderly patients should receive oxaliplatin, a standard component of adjuvant chemotherapy that is known to cause serious side effects.

Researchers  examined health records from more than 8,500 patients with stage II or III colorectal cancer who underwent surgery followed by chemotherapy between 2014 and 2016. Patients were divided into two groups: those treated with oxaliplatin-based combinations, and those given standard chemotherapy alone. Using advanced statistical methods, the researchers systematically tested whether an age threshold existed at which oxaliplatin stopped providing survival benefits.

The results were decisive. In stage III patients aged 70 or younger, oxaliplatin reduced the risk of death by 41%, boosting five-year survival from 78% to nearly 85%. But in those older than 70, oxaliplatin did not improve survival and was linked to higher rates of treatment discontinuation. In fact, almost 40% of older patients receiving oxaliplatin stopped chemotherapy early, often due to toxicity. For stage II patients of any age, oxaliplatin showed no added survival benefit.

The most important point is that oxaliplatin improves survival only in patients with stage III colorectal cancer who are aged 70 years or younger. Beyond 70, the benefit disappears, and oxaliplatin is associated with higher discontinuation rates due to toxicity.

These findings have immediate real-world applications.

Oncologists can use this age threshold to make more precise, evidence-based choices about whether to add oxaliplatin, avoiding unnecessary toxicity in patients unlikely to benefit.

The broader significance extends to health care policy. Avoiding ineffective chemotherapy in older patients may help reduce costs, complications, and hospitalizations. Health systems could redirect resources to therapies and supportive care that make a greater difference in survival and quality of life. The research also sets the stage for longer-term changes in global cancer care.

Jun Woo Bong et al, Older Age Threshold for Oxaliplatin Benefit in Stage II to III Colorectal Cancer, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.25660

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 9:30am

Grue jay? Rare hybrid bird identified 

Biologists who have reported discovering a bird that's the natural result of a green jay and a blue jay's mating, say it may be among the first examples of a hybrid animal that exists because of recent changing patterns in the climate. The two different parent species are separated by 7 million years of evolution, and their ranges didn't overlap as recently as a few decades ago.

They  think it's the first observed vertebrate that's hybridized as a result of two species both expanding their ranges due, at least in part, to climate change.

Past vertebrate hybrids have resulted from human activity, like the introduction of invasive species, or the recent expansion of one species' range into another's—think polar bears and grizzlies—but this case appears to have occurred when shifts in weather patterns spurred the expansion of both parent species.

Hybridization is probably way more common in the natural world than researchers know about because there's just so much inability to report these things happening.

The researchers did not opt to name the hybrid bird, but other naturally occurring hybrids have received nicknames like "grolar bear" for the polar bear-grizzly hybrid, "coywolf" for a creature that's part coyote and part wolf and "narluga" for an animal with both narwhal and beluga whale parents.

Brian R. Stokes et al, An Intergeneric Hybrid Between Historically Isolated Temperate and Tropical Jays Following Recent Range Expansion, Ecology and Evolution (2025). DOI: 10.1002/ece3.72148

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 9:16am

The researchers further found that sex-specific genes often occur in "modules" that are regulated together. Evolution therefore alters sex differences not by changing single genes, but by rearranging whole networks. The driving force here is sexual selection—the ongoing evolutionary conflict between the interests of males and females. This conflict can never be fully resolved, as every adaptation creates new contrasts.

When applied to human tissues, the method reveals a clear pattern: markedly fewer sex-specific genes than in mice, and even stronger overlaps between men and women. In our species, differences are therefore weaker, further undermining the idea of a strict binary classification.

The study concludes that while the sexual organs show a clear binary pattern, most other tissues display a continuum of sex-specific gene activity—a dynamic spectrum that varies both between species and between individuals.

Sex is therefore not rigid and clear-cut, but shaped by evolution, overlaps and individual differences. Instead of classifying the body strictly as male or female based on molecular features, it should be understood as a complex mosaic.

Chen Xie et al, Fast evolutionary turnover and overlapping variances of sex-biased gene expression patterns defy a simple binary sex classification of somatic tissues, eLife (2025). DOI: 10.7554/elife.99602.4

Part 2

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 9:16am

Our body organs cannot simply be classified as male or female

Biological sex is usually described in simple binary terms: male or female. This works well for germ cells (sperm versus eggs), but for other body organs it is of little help.

A new study shows that our organs form a mosaic of sex-specific characteristics—far removed from the strict division into male and female.

The research shows that in many organs, sex-specific patterns overlap strongly. Only testes and ovaries are clearly distinguishable. All other organs show mosaic-like combinations of male and female characteristics.

Sex-specific genes stand out most strongly in the sexual organs. But in other organs the picture is more complex. In mice, the kidney and liver show large differences, while in humans it is adipose tissue. By contrast, the brain shows only minimal differences in both species—consistent with previous studies of human brain structure.

To capture this diversity, the researchers developed a Sex-Bias Index (SBI). This index summarizes the activity of all male- and female-specific genes in an organ into a single value. While the index shows a clear separation in the sexual organs, in other organs the values are often so close that men and women cannot be distinguished reliably.

For example, a man's heart may be more "female-like" than that of some women. Even within an individual, organs can differ—the heart more female, the liver more male. This results in a mosaic of sex characteristics that contradicts the idea of a clear-cut binary.

The study, published in eLife, also shows that sex-specific gene activity in organs evolves very rapidly—much faster than genes active in both sexes equally. Even between mouse species that diverged less than 2 million years ago, the majority of genes have lost or even switched their sex-specific role.

As a result, when comparing humans and mice, only very few genes retain conserved sex-specific activity. This also means that mouse models are of very limited use when applied to sex-specific medicine in humans.

Part 1

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 7:13am

Carbon credits have little to no effect on making companies greener, study reveals

Many companies across the world use carbon credits as part of their climate strategies to offset emissions. A carbon credit is a certificate that represents the reduction, avoidance or removal of one ton of carbon dioxide from the atmosphere. While organizations claim these credits help them reduce their environmental impact, there is debate about whether companies that buy credits decarbonize faster. However, an in-depth study of 89 multinationals, published in Nature Communications, reveals that companies that purchase credits do not decarbonize any quicker than those that do not.

Voluntary emission offsetting is not associated with positive corporate environmental performance. Therefore, it is not a reliable alternative to regulatory measures, such as compliance carbon pricing, wrote the researchers in their paper.

Researchers examined over 400 sustainability reports and self-reported environmental data from multinational companies working in the oil and gas, automotive and airline industries. These were firms that bought and used roughly a quarter of all carbon credits that were available in 2022.
They then compared how much these companies reduced their emissions between 2018 and 2023 and how ambitious their climate goals were with the amount of carbon credits they purchased. To make sure the company data was accurate, the researchers checked it against major carbon credit agencies.

The study found that, on average, companies spend about 1% of their capital spending on carbon credits, which means they account for a small share of the overall budget. The research also highlights a problem where carbon offsets can compete with internal decarbonization.

For some large-scale off-setters buying large amounts of carbon credits can divert funds from internal projects that would directly cut their emissions. Other companies use carbon credits to meet their goals because it is cheaper and easier than making internal structural changes.

The researchers suggest a way forward, namely a shift away from voluntary carbon offsetting to regulatory measures, such as carbon compliance. This is a government-mandated system where companies must pay for the carbon they emit. The main goal here is to create a financial incentive for companies to reduce their carbon emissions.

Niklas Stolz et al, The negligible role of carbon offsetting in corporate climate strategies, Nature Communications (2025). DOI: 10.1038/s41467-025-62970-w

Comment by Dr. Krishna Kumari Challa on September 19, 2025 at 7:09am

Jaguar swims over a kilometer, showing dams are not absolute barriers to large carnivores

Scientists in Brazil recently recorded evidence that a jaguar visited an isolated island in the reservoir area of the Serra da Mesa Hydroelectric Power Dam in northern Goiás State. The same jaguar had been identified on the mainland, 2.48 km away from the island, back in 2020. Both instances were recorded by camera-trap stations, three on the mainland and one on the island, which were set up for an exploratory jaguar survey. The specific jaguar's identity was confirmed by spot-pattern analysis.

After analyzing possible aquatic trajectories for the jaguar, the researchers found that it had two possible paths. Either the jaguar swam the direct 2.48 km to the island, or used a stepping-stone-like islet, taking a 1.06 km swim, followed by a 1.27 km swim to get to the island.

Previous records indicated a maximum swimming distance of around 200 meters for jaguars. Given the possible paths here, this jaguar had to swim a minimum of 1.27 km, possibly more, shattering previous records. This impressive feat is documented in a new bioRxiv preprint, in which the researchers involved also discuss a newly proposed aquatic-cost scale for assessing the ecological connectivity between landmasses.

It was previously thought that reservoirs, like Serra da Mesa, acted as absolute barriers for large carnivores due to prior instances of predator collapse on islands further than a kilometer away from the mainland. Yet, genetic studies across the Amazon River indicated only partial segregation, suggesting occasional crossings.

The study authors explain, "These rare events suggest that, under favorable conditions (e.g., warm water, low currents, presence of stepping-stone islands), large felids may occasionally exploit aquatic corridors that appear to be initially insurmountable."

The research team proposes a new ordinal aquatic-cost scale for modeling connectivity between landmasses, described by low/medium/high cost ranking for water crossings. Low cost was defined as less than 300 m; medium as 300–1,000 m with stepping-stones; and high as greater than 1,000 m of open water. This scale is meant to help inform future hydropower impact assessments and corridor planning for jaguar conservation.

Leandro Silveira et al, Kilometre-scale jaguar swimming reveals permeable hydropower barriers: implications for conservation in the Cerrado hotspot, bioRxiv (2025). DOI: 10.1101/2025.09.05.674446

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