Hello Health Rounds readers! Today we feature news of an experimental blood test that may finally allow for easy detection of ovarian cancer before it spreads in the body. We also share findings that might eventually help stave off cognitive decline, as well as results from two new studies on the impact of wildfire smoke.

In breaking news, see these stories from our Reuters journalists: Swiss ministers meet with pharma executives amid tariff uncertainty; US judge blocks Trump religious exemption to birth control coverage; US alcohol consumption at record low as health concerns rise; one in four US adults with diabetes used a GLP-1 drug last year and US patients cut doses and maybe vacations to stay on weight loss drugs.

Also: France recalls soft cheeses after two suspected deaths from listeriosis; Uruguay's lower house of parliament votes in favor of euthanasia and Gambian police charge three women after death of newborn girl linked to female genital mutilation.

Apple will bring a blood oxygen measurement feature to some of its watch models via a software update after receiving approval from the U.S. government amid a protracted legal dispute over the technology, it said on Thursday.

An experimental blood test detects early-stage ovarian cancer in patients with vague symptoms that would likely be misdiagnosed using currently available methods, researchers said in a new report.

Ovarian cancer is the fifth leading cause of cancer-related deaths among women, largely due to delays in diagnosis until after the disease has spread in the body, at which point it’s harder to treat, according to the researchers.

More than 90% of patients with early-stage ovarian cancer experience symptoms that can be mistaken for benign conditions, such as bloating, abdominal pain, and digestive issues.

Not only have there been no reliable blood tests for these patients, but existing invasive tests often miss early-stage ovarian tumors, the researchers noted in Cancer Research Communications.

Using machine learning tools, the researchers identified multiple biomarkers - from across a wide range of molecules and processes in the body - that could be combined into a single test that detects all sub-types of the disease, at all stages, they said.

Trialed at a large medical center on blood samples from nearly 400 women with possible symptoms of ovarian cancer, the test was 92% accurate at identifying those with any stage of ovarian cancer and 88% accurate at identifying those with Stage I or Stage II disease, according to the report.

Oriana Papin-Zoghbi, chief executive officer of the company developing the new test -Denver, Colorado-based AOA Dx - said the findings show its potential to aid “in making faster, more informed decisions for women who need urgent clarity during a challenging diagnostic process.”

The blood-brain barrier gets leakier with age, contributing to memory deficits – and new discoveries of the mechanisms behind this process might lead to new ways of preventing cognitive decline, researchers say.

The blood-brain barrier - a layer of tightly-junctioned cells lining the brain’s blood vessels - keeps viruses, bacteria and toxins out while allowing helpful nutrients and chemicals in.

“Basically, it’s a mechanism that separates the central nervous system from everything else,” study leader Yulia Komarova of University of Illinois Chicago said in a statement.

In previous research, Komarova and her colleagues found that removing a protein called N-cadherin from the cells lining blood vessels made the vessels leakier in the brain. In a new study published in Cell Reports, her team found that mice without N-cadherin could learn tasks as well as normal mice, but they quickly forgot what they learned.

In further experiments, they found when N-cadherin proteins on neighboring cells interact, they stabilize a protein, called occludin, which helps form the tight junctions in the blood-brain barrier that maintains the integrity of the blood-brain barrier.

Examining human brain tissue collected during epilepsy surgeries, the researchers found that samples from patients in their 40s and 50s had lower levels of N-cadherin and occludin than samples from patients in their late teens and 20s.

Komarova’s team is now investigating whether steps in the signaling pathway activated by N-cadherin could be therapeutic targets.

“This paper shows that actually there might be a much bigger therapeutic window for treatment of any age-related cognitive decline condition,” she said.

Previous studies may have underestimated the number of deaths related to wildfire smoke in Europe by as much as 93%, according to a report in The Lancet Planetary Health.

In new research, using daily mortality records from 654 contiguous regions in 32 European countries, researchers found that for every 1 microgram per cubit meter increase in wildfire smoke particles, all-cause mortality rose by 0.7%, respiratory mortality by 1%, and cardiovascular mortality by 0.9%.

Annually since 2004, short-term exposure to wildfire pollution was responsible for an average of 535 deaths from all causes, the researchers calculated – while estimates in previous studies had put that number at around 38 deaths per year, they said.

“Human-driven climate change is one of the main causes of the rising frequency and intensity of wildfires, as it creates favorable conditions for their spread and increases the number of days with very high or extremely high fire risk,” study leader Anna Alari of the Barcelona Institute for Global Health said in a statement.

“Improving estimates of (wildfire smoke related) mortality will help better track the burden of this climate change-related threat to public health.”

A separate study found that as wildfire pollution levels rise, firefigh