of life-span-shortening and incidence of neoplasms.
When plotted against dose,
life-span-shortening and bone sarcoma induction were not linear over the whole
dose range observed.
Life-span-shortening and tumour induction appeared to be
equally sensitive indicators of radiation damage.
There was a good corres-
pondence between life-shortening and tumour induction up to a dose of 880 yCi/kg
but at still higher doses, in spite of a decreased incidence of the bone tumours, life-span further decreased, showing the beginning of a specific nontumorous mechanism of death.
129.
Finkel's [F5] data were reanalised by Mays and Lloyd [M11].
Mice dying
with bone sarcoma had a median life-span from injection to death which decreased rather regularly with increasing average skeletal dose, owing to a shorter latency time of the bone sarcoma incidence at higher doses.
1life-shortening induced by single injections of
An effect of
995, (1.0 or 0.2 pCi/g) was also
described by Van Putten and De Vries [V2] on (CBAxC57BL)F1 hybrid female mice
and these data plotted as the percentage of the control life-span were rather
close to those of Finkel et al.
130.
[F5].
Similar observations can be made regarding the rat data of Moskalev,
Streltsova and Buldakov [M16] as reanalysed by Mays and Lloyd [M11], since the
average time from injection to death tended to lengthen as the dose decreased
from 500 to 0.005 pCi/kg.
Brooks et al.
A dose-related life-span-shortening was reported by
[B12] in hamster injected with 90.5 (0.2 to 5.0 pCi).
The 60
per cent survival times ranged from 90 days with 2.0 uCi/g to 1100 days at 0.2
uCi/g.
In this species, however, myeloproliferative diseases rather than os-
teosarcoma were the most common pathological conditions observed.
131.
Another volume seeker, Ce, was studied in single injections by Finkel
et al.
[F5], and her data were also reanalysed by Mays and Lloyd [M11].
They
were able to show that median survival time from injection to death in mice
dying with bone sarcoma declined with increasing dose owing to a progressively
early appearance of the bone tumours.
132.
Sarcoma incidence in the bone tissue and life-span-shortening were eva-
luated as a function of dose, dose rate and time in beagle dogs fed from mid
gestation to 1.5 years of age a diet containing 900 [M17].
Under these con-
ditions the observed life-span-shortening was attributed mostly to radiationinduced tumours.
Also, in the same paper a reduction of the delay time in the
i