Kirschner Medical Corp.

This Timonium-based manufacturer of medical equipment reported an upswing in profits and revenues for the quarter that ended March 31.

A company statement said that Kirschner had improved profits and revenues in its core domestic orthopedic and medical video businesses.

Kirschner primarily develops and manufactures medical equipment that has applications in the field of orthopedics.

In addition to its facilities in Timonium, the company has operations in Marlow, Okla.; Hopkinton, Mass.; Fair Lawn, N.J.; Delray Beach, Fla.; and Valencia, Spain.

Potomac Electric Power Co.

Continued mild weather cut power sales by nearly 2 percent in the first three months of 1991 for this Washington-based electric utility.

Pepco, which serves Prince George's and Montgomery counties in Maryland, said net income rose 14 percent to reach $6.9 million for the first quarter. During the same quarter last year, the utility had net income of $6 million.

Earnings applicable to common stock rose slightly less -- 12.7 percent -- from the year-ago period and reached $4.2 million.