LOS ANGELES, May 1, 1986 (UPI) - An American expert in bone marrow transplants, the only treatment for radiation sickness, left Thursday for the Soviet Union at Moscow's invitation to help victims of the Chernobyl nuclear catastrophe.
''I don't know how long I'll be gone. It could be weeks, even months,'' said Dr. Robert P. Gale of UCLA as he left for Moscow, where he was to arrive Friday night.
Gale said he was going alone to discuss with Soviet doctors American innovations in bone marrow transplantation and assess the radiation exposure of people suffering from the reactor's fallout.
Bone marrow transplantation often is used to successfully treat leukemia and other malignancies of the blood.
Gale said that bone marrow, the soft tissue that fills the cavities of bones and the site of red blood cell production, is highly sensitive to radioactivity.
The doctor explained that it often takes years for leukemia to develop, but people who have received massive doses of radiation may show signs of ''bone marrow depression'' within three weeks.
Bone marrow transplantation is the only way to treat radiation sickness, Gale said.
A bone marrow transplant for a leukemia victim entails giving the patient a high dose of radiation to destroy all bone marrow cells. The patient then is infused with healthy bone marrow from a matched donor.
''In this case the people have received the radiation as the result of a nuclear accident and very possibly can be rescued by a bone marrow transplant,'' Gale said.
''I don't know much about their (the Soviets') experience in bone marrow transplantation. They haven't published their results in medical journals. But some Soviet doctors have performed bone marrow transplants, I understand.''
The International Bone Marrow Transplant Registry in Wisconsin, of which Gale is president, contacted Armand Hammer, chairman and chief executive officer of Occidental Petroleum Corp., and asked him to intervene in attempts to offer assistance to the Soviets in the disaster.
Gale said Hammer contacted Soviet leader Mikhail Gorbachev Tuesday offering to sponsor and pay all expenses for the UCLA expert to consult with Soviet doctors.
''We got notification from the Soviet Embassy in Washington that Dr. Gale will be gladly received,'' said Occidental spokesman Frank Ashley.
Ashley said Gale will ''assess what will be needed'' regarding health care for Soviet people exposed to radioactive materials resulting from the worst nuclear plant disaster in history.
Hammer is chairman of President Reagan's cancer panel and has worked closely with Gale on several projects, Ashley said.
The International Bone Marrow Transplant Registry, based in Milwaukee, is the only one of its kind in the world, maintaining computer files to help find bone marrow donors.
''The hope is that the registry will be able to help find bone marrow transplant donors through its extensive computer files,'' said Dr. Mortimer Bortin, head of the registry. ''The registry is unique in that it is a truly successful example of international scientific cooperation.''
The registry has been in operation for 15 years and has received data from more than 150 transplant teams throughout the world. Detailed information on 4,600 patients has been entered into the registry and reports are accumulating at the rate of 1,200 patients annually. Transplant centers participating in the registry enter some 400 clinical factors on each patients.
Some of the contributions of the registry include evaluating the status of bone marrow transplantation by analyzing world results for a variety of diseases, identifying for the first time genetic factors that influence the risk of developing leukemia, and identifying reasons for differences in results between transplant teams.