Bernice Loiacono remembers the time she stopped by early at the home where her son Justin, now 8, was in child care. She found that he had received so little attention that his diaper had not even been changed.

For any parent, such a scene would bring frustration and hurt. But for Loiacono, whose son is autistic and mentally retarded, the frustration was compounded because few child-care operations can accommodate a child with such special needs.

Montgomery County officials broke ground last week in Silver Spring on the kind of center that could have helped Justin. It is the state's first day-care center designed to integrate mentally and physically disabled children with their non-disabled peers.

The Karasik Child Care Center, to open in August 1991 at 10611 Tenbrook Dr., will serve 60 to 80 children. Half the slots are earmarked for children with special needs.

The center will be fully accessible to wheelchairs and will bring children together in much the same way that mainstreaming programs do in the public schools.

The center, named for Monroe and Joan Karasik, a Chevy Chase couple with a long record of support of child care and the interests of the mentally retarded, will also provide hands-on training for day-care providers interested in working with the disabled.

Charles L. Short, director of the county Department of Family Resources, said that as part of the training program, Montgomery College will work with day-care providers around the county to provide a "laboratory" to educate and show them firsthand how to care for children with special needs.

"There's nothing like this training program in the state," said Monroe Karasik.

"It's really been needed for some time and we're glad it will be happening here," Short said.

Both disabled and non-disabled children will benefit, officials said. Disabled children will be able to learn social skills from normally developing children while non-disabled children will get a chance to meet and know disabled children, Short said.

"For the disabled, this will be a new, healthier, more positive way to view themselves," Short said.

Montgomery County donated the land for the Karasik center, which is next to the Montgomery Primary Achievement Center, a day school for special-education children operated by the Montgomery County chapter of the Association for Retarded Citizens.

The state will pay half of the center's estimated $900,000 construction costs, with the county and federal block grants supplying the rest of the money.

While publicly funded day-care centers by law cannot discriminate against children with special needs, private facilities are under no such obligation to accept such children. The problem of finding care for disabled children is exacerbated by widespread shortages of quality child care at prices most families can afford.

Recent studies have indicated that the overwhelming majority of day-care centers in Maryland are inaccessible to the disabled, with providers either unable or unwilling to care for children who are deaf, unable to feed themselves or unable to walk. This situation exists as de-institutionalization has kept more youths at home and as more families have two adults working outside the home.

Short, whose 9-year-old son is blind, knows the sacrifices that must be made. His wife relinquished her career to care for their son.

Loiacono, who works at the National Institutes of Health, said she has been able to keep working because her bosses allow her a great deal of flexibility.

"If I were anywhere else, I just don't know," Loiacono said.