A US team analyzed the genetic activity of individual brain cells from 15 men and 15 women and found 133 genes that showed consistent differences. Although biological sex explained only a small part of the differences they found when comparing all the brains, variants in many of these genes have been associated with neuropsychiatric and neurodegenerative disorders—such as ADHD, schizophrenia, depression, and Alzheimer's—suggesting that sex differences could play a role in the distinct risk men and women have of developing certain diseases. The authors, however, acknowledge that the sex-related differences in their study could stem from differences in socialization and experience. The results are published in Science.  

A review of studies conducted by the Cochrane Collaboration analyzed data from 17 clinical trials involving more than 20,000 participants who had been treated with amyloid-targeting drugs—such as lecanemab or donanemab—at a relatively early stage of Alzheimer’s disease. Results at 18 months of treatment show that “the absolute effects on cognitive decline and the severity of dementia were nonexistent or negligible, falling well below the thresholds established for a clinically meaningful difference,” according to a press release. Furthermore, the review concludes that these drugs likely cause more brain inflammation and microbleeds than the placebo.

The latest forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) suggest that there is a likelihood that the phenomenon known as El Niño will return this year and that it will do so with greater intensity. In Europe, for June through August, the forecast indicates a slight tendency toward below-average precipitation in the northeast of the continent. As for the Iberian Peninsula, temperatures are expected to exceed the top quintile of the seasonal average. Although it is not yet certain that this will occur, forecasts for the coming months will either confirm or rule it out.

A study with Spanish participation has discovered in mice that semaglutide can improve the condition of non-alcoholic fatty liver disease not only through weight loss, but also independently, which would explain why some patients improve with minimal weight loss. “We are not saying that weight loss is unimportant, as many things improve when patients lose weight. But now we know that weight should not be the only measure of success, because GLP-1 drugs will improve liver health regardless of whether the patient loses weight or not,” the authors, who published the results in Cell Metabolism. 

A team from the United States has analysed the performance of 21 large artificial intelligence (AI)-based language models—including ChatGPT, Gemini and Grok—for clinical diagnosis. Their conclusions are that, despite advances in these models, their reasoning capabilities remain limited for initial diagnosis and that they should not be relied upon without the supervision of a medical professional. According to the authors, who published their findings in JAMA Network Open and aimed to “help distinguish reality from hype in the use of these tools”, the results “reinforce the idea that language models in healthcare still require human intervention and very rigorous supervision”.

Permanent splits in chimpanzee groups are extremely rare—an event that occurs once every 500 years, according to genetic evidence. The journal Science reports on the split of the largest known group of wild chimpanzees following 30 years of observations. This involves the Ngogo chimpanzees in Kibale National Park (Uganda). The group shifted from cohesion to polarization in 2015 and eventually split into two distinct groups in 2018. From that point on, violence escalated, and members of one group killed at least seven males and 17 infants from the other. In the 1970s in Gombe (Tanzania), another case of this type was documented, but the chimpanzees had been fed by humans-

For the first time, CAR-T cell therapy has been used to treat a patient with three different autoimmune diseases – autoimmune haemolytic anaemia, immune thrombocytopenia and antiphospholipid syndrome – which were life-threatening and had resisted years of treatment. The patient, who previously required daily blood transfusions, has been in remission for a year without the need for further treatment since then. The case report, published in the journal Med, suggests that these therapies may help treat complex and severe autoimmune diseases. 

GLP-1 medicines for the treatment of obesity show considerable variability between individuals. Using data from 23andMe, scientists at this genetic testing company conducted genome-wide association studies in nearly 28,000 people treated with these drugs, analysing self-reported weight loss and adverse effects. Their findings, published in Nature, identified variations in two genes involved in gut hormone pathways that regulate appetite and digestion, although the authors caution that the effects of genetics appear to be modest.

Neuromuscular taping, or Kinesio taping, is widely used to relieve joint and muscle pain and improve range of motion. However, a meta-analysis published in the journal BMJ Evidence-Based Medicine concludes that it may not be as effective as previously thought. This adhesive tape may provide immediate or short-term benefits, but the current evidence is “highly uncertain”. The authors conclude that the lack of robust evidence, coupled with the potential for associated skin irritation, could limit its use in clinical practice. 

The 2025 wildfire season was the worst the European Union has seen in the last century. According to a report by the European Forest Fire Information System (EFFIS), managed by the European Commission’s Joint Research Centre (JRC), more than one million hectares were burned last year. Some 43% of that figure was burned in the major fires that occurred in Spain and Portugal during the summer. The report also covers the rest of the European continent, the Middle East, and North Africa, resulting in a total of more than two million hectares of burned area.