_ aor It is of interest to note that Pk 80 (if we have this structure right) has already been used in humans in a dose level of approximately 10 mz/kg/d d, Triple Tracer Study, (H, Foreman, C, Finnegan): In an effort to determine the cause of a variation in results of our triple tracer assays using the phosphate-glass technique, we decided that the likely sources of error were two-fold. First, there was a lack of adequate mixing due to the viscid nature of the samples and, secondly, the loss of activity due to the heating process, We feel we have obviated these difficulties by using a mixture which requires much lower working temperatures (200-300°C.) and which is as fluid as water when it is heated. taining 15% KNO, 3 by°° weight. n with bone. when mixed x It yields Rard, clear, glassy, homogenous samples witplansh’”s cury, Swi at orp tigty/curvg§ ss absor preparing & mass We are nownow prep mixture, e, This mixture is poly-phosphoric acid con- 3 Classification chang the 0 A.» by autkorit ( OMLeg a> Effects of Varyi Snare a eae (Takers of the Red Cells of Mice, (J, Sekine,H. wihaee ste E De, i e- a 2, f O47 ZF the change, and date) " (Signaturé of person waking It was known from previous work (1953) that following a single dose of 300 r whole body radiation, there occurred a sharp peak in red cell cholinesterase on the third and fourth days post-radiation. This work has been extended in another dimension, to include observation of fourth-day values at doses from 15 r to 525 Te doses. This response is obtained at 25 r and all higher There is no systematic relationship between the mean values and the dose, possibly because the numbers of mice dsed were not large enough to being out a small dose-rate difference, However, when individual values are plotted for those doses for which relatively large numbers of mice have been used (36 to 64, at each dose) the appearance of the data suggest that the fourth day high value is a response which at low doses may or may not be made by any individual mouse, while with increasing doses more and more individuals do respond.