Lipid peroxidizing activities in thymus, spleen, testis, kidney, brain and liver were studied in intact as well as in adrenalectomized rats which were exposed to 450 or 650 R of whole-body X-irradiation. Contents of lipid peroxides in these tissues, removed from both control and irradiated rats, were found negligibly small as compared to the amounts of lipid peroxides formed in tissue homogenates during aerobic incubations at 37°C for one hour in the presence and absence of added ascorbic acid. Lipid peroxidizing activities determined by the in vitro incubation, varied considerably between tissues, and no correlation was observed between morphologically defined radiation sensitivity of tissues and levels of lipid peroxidizing activity. The activity in liver increased to a considerable extent for some time after irradiation. A lag period was observed prior to the postirradiation increases in livers of intact but not of adrenalectomized rats irradiated with 450 R. The replacement therapy with cortisol acetate in adrenalectomized rats, did not modify the postirradiation changes. The maximal level of lipid peroxidizing activity in livers of adrenalectomized rats was lower than that of intact rats, a finding that was in contrast to the fact that all of the adrenalectomized rats, but none of the intact ones, died within 5 days after 650 R. Lipid peroxidation, therefore, did not seem to be correlated with the mortality of irradiated animals.

抄録全体を表示

In order to investigate situations of uranium contamination in Kamisaibara village where uranium mines are being developed, measurements have been made on the amounts of uranium flow in the streams since 1963, and uranium contents in soil and in farm produce since 1965 by counting system and fluorimetric method.
As a result, it has been found that the mean amounts of uranium flow in the streams in each year is proved to be higher at the sampling spots where drainages of gallaries and the pilot refinery were disposed, and the amounts were between 5.39 and 204.5 mg per minute. At the spots about 2, 000 m lower reaches from these spots, the detectable amounts were 0 to about 30% as compared with those amounts in each year. In general, the spots where the element can be detected gradually move downward year by year.
The uranium contents in soil sampled in the village were 1.9 to 4.0 μg per g of air-dried soil.
Uranium was detected in all vegetables sampled in the village, and the contents were between 0.1 and 0.67μg per g of ash, while it could not be detected in all the vegetables sampled in Okayama City.
On uranium contents in soils and vegetables, however, no remarkable variation with time could be observed.

抄録全体を表示

Salmon sperm DNA irradiated under various conditions in a reactor was examined in two points, ³²P-retention and hyperchromicity. Observed results show that no essential relationship can be found between the two phenomena. When DNA containing water was irradiated at dry-ice temperature, the ³²P-retention was enhanced with increasing irradiation time (dose).

抄録全体を表示

The 500R whole body X-irradiation inhibited the increase in holo-tryptophan pyrrolase activity which were induced by the single administration of cortisone or L-tryptophan in the adrenalectomized rats. However, no inhibitory effect of X-irradiation was found in the activity of holo-tryptophan pyrrolase which was induced by the combined administration of cortisone and L-tryptophan. It was suggested that the radiation effect on holo-tryptophan pyrrolase formation in the cortisone induction was the result of inhibited conversion of apo-tryptophan pyrrolase to holo-tryptophan pyrrolase, whereas apo-tryptophan pyrrolase formation was scarcely affected by X-irradiation. On the other hand, in the tryptophaninduction an inhibition occurred in other processes, presumably in apotryptophan pyrrolase formation. The mechanism underlying the elimination of inhibitory effects of X-irradiation under the coexistance of cortisone and tryptophan was discussed.

抄録全体を表示

Cesium-137 concentration in Japanese beer was determined for the samples of 1959 through 1967. It was found that the level of this nuclide in beer depends on the fallout rate to a great extent and the peak value in beer appears about 1.5 years after the period of the highest rate of ¹³⁷Cs fallout.
The results on certain samples of beer, raw materials (malt, side materials and hops) and the spent residues indicated that almost all ¹³⁷Cs and K contained in raw materials were transferred to beer during its manufacturing process.

抄録全体を表示

A study was made on the loss of the reproductive capacity of HeLa S3 cells irradiated in vitro under both oxygenated and anoxic conditions with D-T neutrons (14 Mev) at 1, 20, 30, 150 and 400 rads/minute at 25°C and 37°C and with 180 kvp X-rays at 100 rads/minute at 37°C.
1) RBE of neutrons measured at a range of 2 to 10% survival was 2.67 ?? 2.62 under oxygenated conditions and 3.83 ?? 4.61 under anoxic conditions.
2) OER was 1.40 for neutrons and 2.16 for X-rays (gain factor was 1.54).
3) Survival rate was dependent on the dose rate of neutrons under both anoxic and oxygenated conditions.
4) There was the evidence of recovery from sublethal damage of neutron irradiation under anoxic and oxygenated conditions after 5 hours.
5) The average size of survival colonies 14 days after irradiation decreased with dose. The abortive colonies increased in number and decreased in average size with dose.

抄録全体を表示

A single dose of ¹³⁷Cs was administered intraperitoneally to rats. The effects of starvation on the whole body retention, daily excretion and blood concentration were studied. During starvation, the urinary and fecal excretion of ¹³⁷Cs were low, and the biological half-life in the whole body was about 3 times as long as that of control. The daily urinary excretion changed very quickly with the change of dietary condition from feeding to starvation and from starvation to feeding. From the data on the urinary excretion and plasma concentration, it was calculated that the renal clearance during starvation was about one third of the control value.

抄録全体を表示

The effect of X-irradiation on ³²P incorporation into both nuclear and cytoplasmic liver RNA of the adrenalectomized rats treated with single or combined inducer, cortisone and L-tryptophan was studied. The single administration of tryptophan as that of cortisone increased the synthesis of nuclear RNA. The tryptophan-induced increase was significantly suppressed by 500 R whole-body X-irradiation, while the cortisone-induced RNA synthesis was not affected by irradiation. No X-ray-induced inhibition of the RNA synthesis was observed in the case of the combined administration of both cortisone and tryptophan, while combined administration of the inducers produced the most marked acceleration of RNA synthesis.
When chromatographic patterns of specific activity of RNA prepared from irradiated animals were compared to those of unirradiated animals, it was found that the synthesis of RNA fractions eluted beyond the absorbancy peak of r-RNA was significantly suppressed by irradiation in the animals treated singly with tryptophan, and that this suppressed synthesis of RNA was not observed in the cortisone induction and was eliminated by the additional administration of cortisone to the tryptophantreated animals.

抄録全体を表示

The effect of partial-body X-irradiation on the goldfish, Carassius auratus, was studied. After anesthetization with MS 222, regions of the head, abdomen or tail of goldfish were exposed to 1 to 16 kR of X-rays from the lateral side. Fish receiving whole-body irradiation served as controls.
Exposures were measured with Radocon and doses absorbed in the body were estimated using fluoro-glass dosimeters inserted in each of three parts of the body whether exposed to, or shielded from, X-rays. Doses absorbed in directly exposed regions (e.g., the abdomen) were around 330 rads and those in the shielded regions (e.g., both the head and the tall) were about 17 rads.
Thirty day-mortality rates increased with increasing integral dose. The commencement of radiation death at about 10 days after partial-body irradiation corresponded with observed histological damage in the intestine and death at around 20 days with damage in the hematopoietic tissues (the head and body kidneys). Skin death due to irradiation occurred considerably later.
From these results it is apparent that mortality rate following partialbody irradiation depends not only on exposure and damage of the directly irradiated part, but also on the dose absorbed in the tissue as a whole.

抄録全体を表示