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

• Both Democrats and Republicans are keeping a close eye on the Massachusetts Senate race to replace Ted Kennedy, which could have big implications for the future of health care reform legislation being ironed out in Congress.

• Gastric bypass surgery appears to lengthen the life span of the most obese recipients of the weight loss procedure, researchers said in a study published this week.

• The way a doctor describe a child's injury as being a "concussion" or a "mild brain injury" has a big impact on how seriously parents take the injury - and the precautions they make their children take, a recent study found.

Tina Reed covers health and the environment for AnnArbor.com. You can reach her at tinareed@annarbor.com, call her at 734-623-2535 or find her on Twitter @TreedinAA.