ALFREDO LEWIS didn't mind when friends or neighbors would ask him for a little medical advice.

People knew Alfredo, a longtime physician assistant with a special interest in orthopedics, was just the person to ask about that bum knee.

"People would say, 'What's wrong with this?' and he would say, 'OK, let me see it,' " said his wife, Margaret McDevitt Lewis.

"He would give them his opinion and advise them to see their doctor. They would see their doctor and come back to him and say, 'You were right.' "

At one time, Alfredo thought he'd like to be a doctor, but after working as a physician assistant, he said, "You know what, I like this better," his wife said.

Alfredo Ricardo Lewis, who assisted in surgery and ran the orthopedic clinic at Bayley-Seton Hospital on Staten Island, N.Y., died Friday. He was 56 and lived in Westhampton, N.J.

Alfredo was forced to retire after heart-transplant surgery in 1999.

The reason Alfredo liked being a physician assistant better than being the physician was that he got to work closer with patients.

"After surgery, a doctor would look in on a patient and go away," his wife said. "But Alfredo took care of the patients. He loved his work."

Despite health problems, Alfredo maintained his normal positive outlook on live.

"When you've known someone for a very long time, from your high school years, when your families have celebrated birthdays together and vacationed on land and sea together, you think you know them as well as you know yourself," said a longtime friend, Michael Days, editor of the Daily News.

"But in the past 10 years, Fred took us all to school as he constantly showed us the steeliness of his God-given character. Despite the constant challenges of life-threatening illnesses, he lived life with grace and with passion and with purpose and with optimism."

Alfredo's beloved grandson Marquis, 18, said, "I wish he had two lives. I wanted to learn more from him. He was one of the best men in my life."

Alfredo Lewis was born in Panama City, Panama, to Elsa Lewis and Felipe Gomez. His father and stepfather, Percival Lewis, are deceased.

He emigrated to Philadelphia at age 8. He graduated from Roman Catholic High School in 1971. He went on to Holy Cross College in Worcester, Mass., then transferred to Hahnemann University in Philadelphia and graduated with a bachelor's degree. He did post-graduate residency at St. Vincent's Medical Center, on Staten Island.

"He was a very positive, upbeat, happy man," his wife said. "He always looked at the good things in life. He was grateful to be here and with his family. He never had a negative outlook."

The Lewises were married in 1983. They enjoyed Broadway shows and concerts in New York City, and at the Mann Center in Philadelphia, of which he was a member. He was also a member of the Philadelphia Museum of Art. As a traveler, he preferred cruises. He turned a few close friends, including Michael Days, on to cruises. "He taught many of us the art of oceanic big-ship cruising," Days said.

He also is survived by a daughter, Aisha Lewis; his mother, Elsa Lewis; a number of siblings here and in Panama, and another grandson, Khalif, 15.

Services: Mass of Christian Burial 11 a.m. Saturday at the Parish of Sacred Heart, 260 High St., Mount Holly, N.J. Friends may call at 10:30 a.m.

In lieu of flowers, donations may be made to Penn Heart Transplant, c/o Dr. Muriel Jessup, Hospital of the University of Pennsylvania, Perelman Center for Advanced Medicine, 2 East Pavilion, 3400 Civic Center Blvd., Philadelphia PA 19104.