Here's a look at some of the top health news being talked about around the U.S. and the world today:

• On Monday, a federal judge in Washington blocked President Barack Obama’s 2009 executive order that broadened embryonic stem cell research. The judge said it violated a ban on federal money being used to destroy embryos, the New York Times reported. According to that article, scientists are scrambling to determine how the ruling will impact their work.

• An experimental vaccine prevented Hepatitis E in all of the patients who received it in a Chinese study, Bloomberg reported. The waterborne illness, linked to poor sanitation, causes jaundice and fever and is especially dangerous to pregnant woman, according to the article. It’s likely one-third of the world’s population has contracted the disease, according to researchers.

• A few Massachusetts towns have given up on marijuana enforcement, the AP reported. A new law passed in November 2008 established a civil fine of $100 for those caught with less than an ounce of the drug. Some officers feel it has too many loopholes to be effective.