Authors:R. Jervis, R. Hancock, D. Hill, and K. Isles
Several features of the new SLOWPOKE+ pool-type nuclear reactor have made it very useful for instrumental neutron activation of tissues, blood and other body fluids.
In this paper are reported results from studies on clinical patients who had malnutrition, cystic fibrosis and other related
electrolyte disorders. Physical conditions in the irradiation sites within the beryllium reflector are such that liquids,
slurries and wet tissues (the types of sample obtained from patients) can be irradiated in sealed polyethylene vials without
pretreatment. This facilitates a precise semi-routine activation analysis for large numbers of samples from patients. A stable
activable tracer technique has been developed to determine the extracellular fluid volume (ECV) of infants. A regulated dose
of sodium bromide is injected into the patient and, following short-term equilibration and dilution of this sample, a small
blood sample is taken, yielding 50 μl of plasma. The plasma bromide concentration is determined by80Br (T=18 m) activation. In order to check the accuracy of this NAA technique, some samples were cross-checked by a microdiffusion
method. The technique has been applied to 230 patients and controls, and has proved to be simple, rapid, accurate and sensitive
for determining ECV to ±6%. Patients with cystic fibrosis (C. F.) were studied with respect to their growth, and their sodium
and electrolyte balance. In related clinical studies, hair and nail clippings from 50 C. F. patients and control children
of the same age groups were activated at SLOWPOKE and Cu, Ca, Br, Cl, K, Na and I, determined for use in differentiating C.
F., along with a number of other elements including Zn, Mn, Al, Ti and Ni which showed little difference. A careful analysis
of the data showed that clear differentiation of all C. F. patients from controls could be achieved by comparing the values
of X-factor. A fairly good correlation of hair and nail concentrations was found for a number of the elements determined,
suggesting that either tissue may be used in future studies.