April 16 (Reuters) - The Dow and the S&P 500 opened

higher on Tuesday, with health insurers leading the charge

following upbeat results from industry major UnitedHealth ( UNH ), while

investors kept tabs on the conflict in the Middle East.

The Dow Jones Industrial Average rose 257.11 points,

or 0.68%, at the open to 37,992.22.

The S&P 500 opened higher by 2.77 points, or 0.05%,

at 5,064.59, while the Nasdaq Composite dropped 28.64

points, or 0.18%, to 15,856.38 at the opening bell.