TOKYO -- Advances in medical treatment for radiation victims give hope that one or more of the three workers severely irradiated last week in Japan's worst civilian nuclear disaster could survive, doctors said yesterday.
Two of the men received more than lethal doses of radiation Thursday in being bombarded with neutrons during an uncontrolled nuclear fission reaction at a uranium processing plant. They remained critically ill yesterday.
But their condition was stable enough that doctors announced plans to give them both transfusions of bone marrow cells using new, noninvasive techniques pioneered on cancer patients.
Both Hisashi Ouchi, 35, and Masato Shinohara, 39, were continuing to suffer from a disastrous decrease in their ability to produce blood cells, among other problems.
Umbilical cord cells
But in an improvement on traditional bone marrow transplants, which were tried with little success on victims of the 1986 Chernobyl nuclear accident, Japanese doctors planned to give Shinohara a transfusion of blood cells from the umbilical cord of a newborn, a technique that avoids the rejection problems common with bone marrow transplants.
Ouchi was scheduled to receive a transfusion tomorrow of stem cells -- immature blood cells that can develop either into red or white blood cells or into platelets -- that would be harvested from the veins of his brother.
The procedure is no more painful than giving blood, so neither the donor nor the recipient requires a general anesthetic -- a big advantage for weakened recipients such as radiation patients.
High risk of infection
Meanwhile, the immune-compromised patient is at high risk for potentially lethal infections, said Dr. Hisamaru Hirai, a transplant specialist on the team that is treating Ouchi at Tokyo University Hospital.
"If we succeed, it would be the first time in the world" that a stem cell transplant has been used to help radiation victims, Hirai said.
Doctors and radiation specialists said that a better understanding of the physiology of radiation poisoning gained from the Hiroshima atomic bombing, Chernobyl and other disasters has helped improve treatment for the victims of the uranium processing plant disaster in Tokaimura, about 80 miles northeast of Tokyo.
In addition, there have been advances in the creation of truly germ-free hospital rooms, infection prevention, intravenous nutrition, life support and methods for maintaining the body's electrolyte balance, said Dr. Shunichi Yamashita of the Atomic Bomb Disease Unit at the Nagasaki University School of Medicine.
The question is whether any of the Japanese patients' bone marrow has survived, American experts said yesterday. If it has, they will reject the grafted cells.
Even if the grafts are rejected, however, they could help the men fend off infections until their own bone marrow recovers, said Dr. Rodney Withers of the University of California, Los Angeles.
Hoping for a miracle
In a telephone interview from Nagasaki, Yamashita said: "If Ouchi survives, it would be close to a miracle. But Japanese medicine can do miracles -- I hope."
Japan has a poor reputation in emergency medicine, and leading specialists have publicly chastised both the government and the medical profession for allowing patients to die because of slow transportation and lack of well-trained emergency medicine practitioners.
But in this disaster, the emergency medical response was excellent, with three severely injured men quickly taken by helicopter to be treated by radiation experts at the National Institute for Radiological Science in Chiba prefecture, Yamashita said.
Doctors can only estimate how much radiation Ouchi and his colleagues actually received, because in one of the numerous safety violations that have emerged since Thursday's accident, the men were not wearing badges designed to keep a tally of their radiation exposure.
Badges left behind
Authorities searching the plant for evidence yesterday found the badges about 150 yards from the room where the workers were dumping buckets of high-grade uranium into a tank instead of piping the uranium solution in gradually through monitors, as the nuclear-fuel-producing facility was supposed to do.
Experts have estimated that Ouchi received about 17 "sieverts" of radiation; Shinohara, about 10 sieverts; and their supervisor, Yutaka Yokokawa, 54, about three.
Seven sieverts is considered a lethal dose, although some victims of the 1945 U.S. atomic bombing of Hiroshima died after receiving two sieverts, said Dr. Nobuo Takeichi, a radiation specialist who also has helped treat child radiation victims from Chernobyl.