(Left to right): Heidi and Hans-Juergen Koch/Minden Pictures; Zephyr/Science Source; Robert Blanken

Top stories: Why Costa Rica’s crocodiles are changing sex and an asthma drug to treat Parkinson’s

Something is changing the sex of Costa Rican crocodiles

After probing and peering at the genitalia of nearly 500 crocodiles in Palo Verde, Costa Rica, a team of ecologists found something odd: The sex ratio was way out of whack, with males outnumbering females four to one among hatchling crocs. The researchers later discovered that the animals’ tissues are tainted with a synthetic hormone that may be causing them to switch sex.

Anti-inflammatory cuts risk of heart attack

A clinical trial of more than 10,000 heart attack patients supports a novel way to protect them from a stroke or a second attack: with drugs that stop inflammation. The approach has been advanced by some scientists for years, but this is the first trial to conclusively show that it works. Cardiologists hailed the study, reported this week, as vindication for the heart attack–inflammation link, which hadn’t been proved in people.

Modified T cells that attack leukemia become first gene therapy approved in the United States

The U.S. Food and Drug Administration this week approved a new cancer therapy that involves genetically modifying a patient’s immune cells to kill leukemia cells. The therapy, developed by the pharma giant Novartis, is the first such treatment to be approved in the United States.

Asthma drug may thwart Parkinson’s disease

When people with asthma have trouble breathing, they may reach for an inhaler containing salbutamol, a drug that expands the airways. Salbutamol may have another beneficial effect—protecting against Parkinson’s disease. Individuals who inhaled the highest doses of salbutamol were about half as likely to develop the devastating neurological condition as those who didn’t take the drug, a new study reveals.

Why some baby bees are destined to become workers—or queens

The saying “you are what you eat” is particularly true for female honey bees, which grow up to be either small, sterile workers or large, fertile queens depending on their diet. Previously, researchers thought that something in the food fed to young queens—a secretion called royal jelly—was what made the difference. Now, a study suggests it’s signaling molecules in the grub of young worker bees that keeps their sexual development in check.