An international team has created a tiny temporary pacemaker, smaller than a grain of rice (1.8 mm × 3.5 mm × 1 mm). The device is resorbable by the body, achieves effective pacing in human and various animal cardiac models, and could be implanted less invasively than existing pacemakers, according to a study published in Nature.

A team led by the Spanish National Cancer Research Centre (CNIO) has shown in mice that a high-fat diet increases metastasis in triple-negative breast cancer, which has the worst prognosis. In addition, it has identified several of the mechanisms that would explain this, such as the activation of platelets and coagulation, which would help the tumour hide from the body's defences and prepare the so-called ‘pre-metastatic niche’. According to the researchers, who published the results in Nature Communications, ‘this mechanism could be extrapolated to other tumour types and other organs’. The results suggest that ‘dietary intervention, together with the control of platelet activity, may increase the efficiency of certain anti-tumour treatments’.

EMA’s human medicines committee has recommended not authorising the marketing of Kisunla (donanemab), a drug intended for the treatment of early-stage Alzheimer's disease. The committee considered that the benefits of this drug were not great enough to outweigh the risk of potentially fatal events. In recent years, several patients have died due to microbleeds in the brain.

A powerful 7.7 magnitude earthquake with an epicentre near the city of Mandalay in Myanmar (formerly Burma) has been felt in cities as far away as Bangkok, the capital of Thailand, more than 1,300 kilometres away. The earthquake was shallow - 10 kilometres - and has been followed by several aftershocks, according to the US Geological Survey (USGS).

A team from France has studied the intestinal microbiota of elite athletes with high aerobic capacity (footballers and cyclists). The data indicates that they have less bacterial diversity and that the transplantation of faeces from athletes to mice improves metabolic parameters such as insulin sensitivity and glycogen deposits in the muscles. The results are published in the journal Cell Reports.

Cuts in international HIV funding could cause between 4.4 million and 10.8 million new HIV infections between 2025 and 2030 in 26 low- and middle-income countries. In addition, these funding reductions could result in between 770,000 and 2.9 million HIV-related deaths, according to a study published in The Lancet HIV. Five countries that together provide more than 90% of funding for international HIV interventions - the US, UK, France, Germany and the Netherlands - have announced reductions in funding between now and 2026, the article explains. This includes the immediate suspension, in January 2025, of US funding, which accounted for nearly three-quarters of the total.

In 2024, a team of researchers in China transplanted a pig's liver for the first time, with six genes modified to prevent rejection, into a person who was brain dead. After 10 days, they evaluated the condition of the organ and the recipient. According to the authors, who are now publishing the work in the journal Nature, the results suggest that genetically modified pig livers can survive and function in humans, which could serve as a bridge therapy for patients with liver failure who are waiting for human donors.

A team from Canada and the United States has found a candidate to form part of a new class of antibiotics, lariocidin. This could be effective against multi-resistant bacteria. The finding is published in the journal Nature.

Genome analysis of 11,555 individuals revealed 60 genes involved in congenital heart disease, according to a study published today in the journal PNAS. Congenital heart disease is one of the most common birth defects and affects between 1 and 1.8% of live births.

In marathon runners, the myelin content of specific regions of the brain is reversibly reduced, according to a study carried out in the Basque Country. This observation is consistent with animal evidence suggesting that myelin lipids - a substance that surrounds neurons - can act as energy reserves in extreme metabolic conditions, as detailed by the authors in Nature Metabolism. The analysis is based on magnetic resonance imaging of eight men and two women before and after running a marathon. According to the study, the myelin content was fully recovered two months after the race.