IRRADLVnON AM) Ri.PLACKMKM ()!• i«).M. MARROW, USING >»«Au 

 Table 3. Macroscopic variation of the concenlraiiim of '""Au in bone marrow 



R.ihbil 

 number 



Sites of bone marrow 



Resftectiie coiuentiatwm 

 (xC/g per mC/kg 



1 Ic Right femur, left femur 2 • 29, 2 • 2 1 



5d Femur, rib 32, 37 



6d Femur niiddlr, femur end, rib, skull 28. 27, 48, 28 



jS doses. Table 4 shows the range, mean and standard deviation of ^ doses 

 for rabbits which died after receiving 2-5 to 3-0 mC/kg. The dose is 

 estimated as that deHvcred to the tissue up to the time of death, so that a 

 part of the variation in the dose delivered could be attributed to variation 

 in survival time. Since, however, the shortest survival time involved is 7 • 5 

 days, when 85 per cent of tlie activity present has decayed, this part of the 



Table 4. Roentc^en doses to liver, bone marrow and spleen 



variation would be small, and for the same reason the figures given could be 

 taken as virtually those for complete decay of the radio-activity. Rabbits 

 which received doses of ^^^Au in excess of 3-0 mC/kg received corres- 

 pondingly larger roentgen doses to tissues. 



Survival 



For non-splenectomized rabljits which received specific doses of 2 to 3 

 mC/kg, out of 7 controls there are 2 or 29 per cent, surviving at the time 

 of writing, and out of 1 4 treated there are 7 or 50 per cent surviving, the 

 shortest time since the dosing being 56 days. It is too early yet to deter- 

 mine survival rates for splenectomizcd rabbits. None of these survivors are 

 showing any outward signs of sickness, although No. 2b did show such signs 

 at 7 to 14 days. 



Table 5 shows details of irradiation, transfusion, and survival time for the 

 five series of rabbits used to the time of writing. Periods of time shown 

 commence in each case on the day of dosing with ^'***Au. For rabbits still 

 alive at the time of writing, the survival time shown is to 6th November, 

 1958. 



60 



