Scientists at a small California biotechnology company reported yesterday that they had developed a process to turn human embryonic stem cells into pancreatic cells that can produce insulin and other hormones.

The work by the company, Novocell, based in San Diego, is a step toward using embryonic stem cells to replace the insulin-producing cells that are destroyed by the body’s immune system in people with Type 1, or juvenile, diabetes. Years of research remain, however, before a therapy developed from this approach can be put to use.

Embryonic stem cells can potentially be turned into any type of tissue in the body, and scientists are trying to figure out how to form various types.

Other researchers have previously reported turning various types of human or animal stem cells into cells that produce insulin. But the new work, published online yesterday by the journal Nature Biotechnology, represents a significant advance, some experts said.

Doctors are already experimenting with transplanting cells from the pancreases of deceased organ donors into people with Type 1 diabetes. In some cases, the transplants relieve the recipients of the need to give themselves daily injections of insulin. But the effect wears off for most patients by two years.

Donated pancreases are scarce, so scientists hope to use stem cells to create insulin-producing cells. People with Type 1 diabetes and their families were among the biggest backers of the effort to create a $3 billion program of stem cell research in California.