Final report-98-ERI-003 identification of population with lifetime 41Ca-labeled skeletons

摘要

In 1997 we first postulated the existence of a special human population that had had their skeletons inadvertently isotopically adulterated in the past. We theorized that the population, and the necessary LLNL accelerator mass spectrometer (AMS) measurement technology, would prove a significant resource in the fight to combat osteoporosis. This LDRD project was to establish such. The project was significantly successful in its initial year, but was not renewed for another and the research is now ended at LLNL. We proposed a three-year program to (1) confirm the magnitude and extent of historical 41 Ca dosing, (2) exactly characterize the long-term 41 Ca signal by comparing it with conventional measurements of skeletal health, and (3) demonstrate the utility of the historically labeled population in evaluating an actual potential therapy for osteoporosis. However, rather than investigate historical records to learn the identity of those inadvertently dosed, find them, and if possible enroll them into a new protocol, this project was to be particularly efficient by making use of a multiyear archive of samples from original, inadvertent 41 Ca-dosing experiments at Creighton University in Omaha, Nebraska. Because the subjects had been dosed in conventional studies of calcium kinetics, much important correlating historical data would also be available for comparison. Measurements of contemporary urine samples specifically provided for this project by selected identified subjects would follow. We discovered a second archive at the University of Texas Southwestern Medical Center. This is potentially a better source of material as the samples were generated in numerous historical evaluations of actual osteoporosis therapies in which 41 Ca-impure radiotracers were used. The therapies might now powerfully be retrospectively evaluated, both to contribute to our understanding of the therapies and to highlight the potential of the use of 41 Ca tracer and LLNL measurement.