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Volume 5, Issue 1
Displaying 1-10 of 10 articles from this issue
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Kiyoshi HIRAKI, Shozo IRINO, Susumu SOTA, Koji IKEJIRI1964 Volume 5 Issue 1 Pages 1-11
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSThe incidence of leukemia in the RF mice exposed to a single whole body irradiation of 350 r X-rays was 77.4%, 41 out of 53 mice. Of them, 20 animals developed the thymic type and 20 others the non-thymic type lymphocytic leukemia, while only one developed myelogenous leukemia. Comparative studies were made on the thymic and non-thymic type leukemia.
By inoculating the cell-free filtrates from the leukemic RF mice induced by a single whole body X-irradiation to the newborn mice of the same strain younger than 16 hours old, two (16.7%) of the twelve inoculated animals developed leukemia 375 and 374 days respectively after the inoculation. In the inoculation of the cell-free filtrates from normal mice to the newborn mice of the same strain, and in the non-irradiated control mice not a single case of leukemia developed. On the basis of these findings a discussion has been made on the role of virus in the induction of leukemia by X-ray irradiation.View full abstractDownload PDF (614K) -
Hironobu WATANABE, Mikio YAMASHITA, Hiroyuki TSUBOTA1964 Volume 5 Issue 1 Pages 12-22
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSRain water radioactivity in each rain fall was analyzed by gammaray spectrometric method for the gamma-emitting nuclides with intermediate half lives during the period from October 1961 through December 1962. The gamma-ray spectra observed were generally featured with three predominant photopeaks at around 0.14 MeV, 0.5 MeV and 0.75 MeV, which mostly attributed to (141Ce, 144Ce), (103Ru, 106Ru-106Rn) and (95Zr+95Nb) respectively in comparatively younger fallout. Analytical data were presented together with graphical explanations.
Decay rate of the 0.14 MeV peak observed in samples from March through July 1962 revealed that there was little influence of fallout due to the Pacific Test Series in the same period. A clear peak of 95Zr+95Nb in the cumulative deposition was shown in early summer with a maximum value of about 200 mμc/m2, probably due to frequent rain falls in this period.
The data presented could be useful to estimate approximately the fallout deposition of gamma-emitters with intermediate half lives in other areas in this country with some assumptions.View full abstractDownload PDF (407K) -
Takeo MURAI, Tadashi NAKAMURA, Akira YAMAMOTO1964 Volume 5 Issue 1 Pages 23-34
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSThe plastic scintillator emits fluorescent light of which the quantity is proportional to the absorbed radiation dose in it. And it can be believed that in this phenomenon the energy dependence does not exist. Based upon the above characteristics of the plastic scintillator a new method of the integral dose measurement was developed. A cuboid plastic scintillator of 28 × 28 × 15 cm in size was used as a phantom. It was irradiated by X rays and fluorescent light from the phantom was measured as a direct current using a photomultiplier, thus the integral dose in the phantom was obtained. Our results were relatively well compatible with those obtained by Bewley and his co-workers.View full abstractDownload PDF (586K) -
Kazuo MORITA1964 Volume 5 Issue 1 Pages 35-38
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSAn experiment was carried out to determine the protective effect of orotic acid (uracil-4-carboxylic acid) against X-rays. Orotic acid in dose of 0.05, 0.1, 1.0, 1.7 and 10 mg per mouse was given intraperitoneally to mice before or after a single dose whole-body Xirradiation of 700 r or 550 r, after which the 30-day survival rate was observed. As a result it was concluded that it would be difficult to state that orotic acid has a protective effect against X-irradiation. It may be added that even if a protective effect exists it would be slight.View full abstractDownload PDF (122K) -
Takashi AOYAMA, Teruo KONDO, Masakatsu HORIKAWA, Tsutomu SUGAHARA1964 Volume 5 Issue 1 Pages 39-48
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSIncorporation of halogen analogs of pyrimidine into DNA of the mouse strain L cells enhanced their sensitivity to X-ray irradiation. The maximal radiosensitization was obtained either with 72 hours, incubation in the presence of BUdR alone or 24 hours' incubation in the presence of BUdR and aminopterin before X-ray irradiation. The replacement of thymidine by BUdR in these optimal conditions was approximately 30 %, and a further increase of the replacement up to 50% did not intensify the radio-sensitization. These results may support the view that BU-labeling of single strand of DNA double helix is sufficient to confer significant radiosensitization. The radiosensitivity of the resistant Lγ cells was restored by BUdR incorporation up to the same level as that of untreated original cells.
These observations would contribute to some extent towards the improvement of radiation therapy.View full abstractDownload PDF (429K) -
Hiroyuki TSUBOTA, Taku KOYANAGI1964 Volume 5 Issue 1 Pages 49-55
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSA rapid and sensitive method for the determination of strontium in bone was investigated. Strontium is separated from a large amount of calcium which exists in bone and from interfering ions which depress the strontium emission using cation exchanger with EDTA as an elutriant.
Strontium in the effluent, EDTA solution, can readily be determined by flame photometry without any treatment of effluent, when the enhancing effect of EDTA on the intensity of strontium flame emission is utilized effectively. Using this method, strontium content in bone could be determined from about 0.2g of bone ash with the error below 10% and with the standard deviation of 3.5%. The method would be also used for the analyses of a micro amount of strontium in various calcareous materials.View full abstractDownload PDF (238K) -
Minoru FUJITA, Jun AKAISHI, Junko IWAMOTO, Akira YABE, Yoshiko ICHIKAW ...1964 Volume 5 Issue 1 Pages 56-68
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSThe levels of fission products such as 90Sr, 137Cs, 95Zr, 95Nb, 103Ru and 106Ru in diet and excreta were examined. The experiment started in May, 1962 and ended in Feb., 1963. During the period, seven intermittent samplings of excreta and diet were made. In each sampling, excreta were collected over five consecutive days from four normal human subjects who took the same diet at that time. An exact duplicate of the diet was collected at the same time.
A large NaI(Tl) crystal scintillator and an 100 channel pulse height analyser were used to determine the radioactivities of γ-emitters in ashed samples, but 90Sr and 137Cs were analysed radiochemically.
In general, the value of 95Nb in the diet was highest among all the radioactive fission nuclides, reaching about 60 μμc/day/person in Feb., 1963. The level of 90Sr in the diet varied between 7.0 and 13 μμpc/day/person during the period, and that of 137Cs changed between 13 and 35 μμc/day/person. However, about 1 μμc of 90Sr was always found in 24-hr urine samples, irrespective of the contents in the diet. The activities of 137Cs in the same urine specimens, in contrast to 90Sr, changed between 10 and 31 μμc corresponding to the contents in the diet.
During the period examined, the levels of 137Cs and 95Zr+95Nb in the diet varied according to the changes of the dry fallout in the atmosphere.
The amount of stable potassium and calcium in the diet and excreta were also examined.View full abstractDownload PDF (487K) -
Tamiko IWASAKI1964 Volume 5 Issue 1 Pages 69-75
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSIn recent years much research has been devoted to investigating conditions which change or appear to change the radiosensitivity of living materials. Such studies are of great importance for understanding the steps between the initial absorption of energy and the manifestation of its effects. The dry eggs of Artenaia are very suitable material for the study of the effect of modifying factor on radiosensitivity, because they can be subjected to so much variation in methods of handling them without altering viability.
As the first experiment in a series of papers on sensitivity of Artemia eggs to the γ-irradiation, the delay of hatch and the doseeffect relation in hatchability of irradiated dry eggs, were tested. The eggs were irradiated in the dry state at total doses of 480 kr and 600 kr, and then soaked in 2% NaC1 solution at 27°C. The delay on the development of eggs became greater as the irradiation dose increased. Radiosensitivity based on the hatchability at 72 hour after incubation diminished with dose in a sigmoidal curve. The 50% hatching dose was about 500 kr, and the 100% lethal dose was 900 kr. The low radiosensitivity may be attributed to the low water content and the arrest of metabolism of the eggs.View full abstractDownload PDF (267K) -
Tamiko IWASAKI1964 Volume 5 Issue 1 Pages 76-81
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSThe radiosensitivity of living materials has been found to depend greatly on conditions during irradiation. In this paper, the influences of water content and temperature during irradiation on Artemia dry eggs were examined.
Artemia eggs of various water content were irradiated with γ-rays, and then soaked in 2% NaCl solution at 27°C. The radiosensitivity of eggs on the basis of hatchability increased successively with an increase of water content within 5.8%6 to 54.0%, except that at 9.6% showed a temporary decrease.
The eggs once moistened prior to irradiation were redesiccated to the initial level of water content. Their sensitivity was shown to be almost at the same level of the initial one.
To test the influence of temperature, the eggs were infiltrated with moisture at 0°C and 25°C, and then they were irradiated at low or high temperatures, respectively. There was no significant difference in sensitivity between eggs infiltrated at 0°C and 25°C. However, the sensitivity of eggs, infiltrated at both temperatures, irradiated at high temperature was found much higher than those irradiated at low temperature. These findings have been discussed in relation to similar one in plant seeds.View full abstractDownload PDF (260K) -
Yutaka NAGAYA, Theodor R. FOLSOM1964 Volume 5 Issue 1 Pages 82-89
Published: March 01, 1964
Released on J-STAGE: August 29, 2006
JOURNAL FREE ACCESSMeasurement have been made of several fallout nuclides in selected organisms of the California coast. Hagfish and amphipod are noticeably free from zirconium-95 and contain small amounts of cesium-137 (average 1.2 and 32 uuc/kg-wet). Mussel, a filter feeder, contains less cesium-137 but its zinc-65 and manganese-54 concentrations are remarkable (average 50.2 and 24.5 uuc/kg-wet). Zinc-65 concentration in amphipod is about 5 times of mussel but it does not contain manganese-54.View full abstractDownload PDF (308K)
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