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Executive Summary 1997

This Annual Report covers the period from October 1, 1996, through September 30, 1997, and includes both scientific and administrative accomplishments of the United States Transuranium and Uranium Registries during this period. As of September 30, 1997, the Registries had a total of 889 registrants, of whom 356 were deceased, 270 living, and 263 inactive. The median age of the living active registrants was 73 years, with approximately two thirds older than 65. The program underwent its regular annual human subjects review and carried out its annual review and updating of its internal policies and procedures. Two new Advisory Committee members, Father Frank Costello, S. J., and Professor Frank Gilliland, were appointed to replace retiring Committee members. A retrospective evaluation of the USTUR publication experience revealed that since their inception, the Registries have published a total of 220 documents of which 108 have been articles in the open peer reviewed scientific literature. The Registries also responded to approximately 60 mail or telephone public inquiries.

The body of the report includes a comprehensive tabulation of actinide concentrations determined in postmortem tissue donations from more than 150 routine donors to the Registries. Also included is a tabulation of the causes of death and tissue availability through the National Human Radiobiology Tissue Repository for all USTUR cases to date.

In addition to the ongoing collaboration with the Russian Institute of Biophysics, the other scientific studies Registries participated in 18 active specific research projects involving 14 institutions during the reporting period. The Russian collaboration included a radiochemical intercomparison with the Dosimetry Registry of the Mayak Industrial Association, which validated the Russian data while at the same time identifying great variation (i.e. lower precision) in their measurements as compared with the USTUR.

Studies of gene transfection carried out collaboratively with Pacific Northwest National Laboratory demonstrated that transient infection of reported genes into malignant melanoma cells can be induced by lithotriper shockwaves, both in vivo and in vitro. Gene expression with shockwaves was 15 fold greater than controls, and persisted for at least a day in most treated tumors suggesting that combined shockwave and gene therapy may be an effective modality for the treatment of cancer.

The continuing evaluation of data in the National Radiobiology Archives from animal studies previously carried out and now terminated indicated that plutonium concentrations in dogs were of sufficient magnitude to be useful autoradiographic studies designed to track the distribution and sequestration of plutonium in lung and liver. This work is basic to further work with regard to plutonium sequestration in scar tissue. Other research possibilities offered by the animal data include study of genetic material in somatic cells to determine tumor induction and tumor induction mechanisms. Studies of lung cancer induction in beagles experimentally given inhalation doses of 238Pu or 239Pu indicates that there is an apparent threshold dose for lung cancer induction, and that the incidence of first or initial tumors saturates at a fairly moderate dose level.

Examination of the soft tissue concentrations of plutonium relative to the concentration the liver in seven whole body donors showed considerable variability, but generally were considerably lower than in the liver, suggesting lower doses and hence lower stochastic risks. Trachea, spleen, pituitary and testes typically had higher concentrations relative to other soft tissues excluding liver.

Radiochemical analysis of the second portion of a placenta from a women with a prior history of exposure to plutonium via an acute inhalation intake were consistent with earlier measurements which showed a significantly greater concentration of plutonium in the placental tissue than in the placenta from a matched control from the general population, although there were differences in the magnitudes of the values received from the two laboratories. The specific analytical procedures used by the two laboratories are being examined to determine the cause of these differences.