Alzheimer’s Tied to Mutation Harming Immune Response

By GINA KOLATA

A mutation to a gene, TREM2, is suspected of interfering with the brain’s ability to prevent the buildup of toxic shards of a protein that accumulate in plaques on the brain.

• Health Guide: Alzheimer's Disease

New Infection, Not Relapse, Brings Back Lyme Symptoms, Study Says

By DENISE GRADY

Research comparing the genetic signatures of Lyme bacteria in people who had the disease more than once challenges the notion that it has a tendency to turn into a chronic illness.

• Health Guide: Lyme Disease

F.D.A. Chief Seeks Expanded Authority To Improve Safety of Drug Compounders

By SABRINA TAVERNISE

Pharmacy compounding has come under a spotlight in recent months, after a center produced pain medicine contaminated with fungus that caused a national meningitis outbreak.

Health Law Has States Feeling Tense Over Deadline

By ABBY GOODNOUGH and MICHAEL COOPER

States have until Friday to tell the Obama administration whether they want to create their own health insurance exchange — a deadline Republican lawmakers had hoped would not come to pass.

Caffeinated Drink Cited in Reports of 13 Deaths

By BARRY MEIER

A high-caffeine energy drink, 5-Hour Energy, has been cited as possibly being involved in 13 deaths, according to Food and Drug Administration records.

Heart Medications May Also Calm Nerves, Keeping Them Banned

By BILL PENNINGTON

The permissibility of beta blockers in golf’s top level has come into focus anew this week after Charlie Beljan won a PGA Tour event Sunday, two days after being hospitalized with a panic attack.

• On Course, Low Stakes Don’t Mean Less Anxiety