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Volume 18 (1977)
- Issue 4 Pages 251-
- Issue 3 Pages 165-
- Issue 2 Pages 93-
- Issue 1 Pages 67-
Volume 18, Issue 4
Displaying 1-13 of 13 articles from this issue
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T. MASUDA, Y. MURATA, H. YAMANAKA, M. KONDO1977 Volume 18 Issue 4 Pages 251-257
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSIn the course of study on photoreduction of ferricytochrome c, transient absorptions of photolyzed indole were found over the range 600-800 nm, where usually the absorption of hydrated electrons is observed. The assignment of the absorptions was achieved by comparing the rate constants for decay of the absorptions found in this work with those for the absorptions already assigned and reported. The absorption around 720 nm observed in N2-saturated neutral solution was assigned to the electron-adduct formed by the reaction of indole with hydrated electron. In acidic solution, the absorption peak near 690 nm was observed and assigned to H-adduct of indole. The peak near 710 nm observed in N2O-saturated solution was assigned to OH-adduct, which was produced by the reaction of indole with hydroxyl radical converted from hydrated electron by the reaction with nitrous oxide.View full abstractDownload PDF (281K) -
T. MASUDA, Y. MURATA, K. YAMAUCHI, M. KONDO1977 Volume 18 Issue 4 Pages 258-267
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSPhotoreduction of ferricytochrome c in aqueous solution was investigated by flash photolysis in the presence and absence of indole or o-dimethoxybenzene, which were known as efficient electron-donors in photochemistry. Formation of ferrocytochrome c was confirmed with its characteristic absorption spectrum. In the presence of the electron-donor, the reduction was not completely depressed by a sufficient amount of nitrous oxide and about 20 per cent of reduction was still observed. The reduction was also observed in the absence of the electrondonor. The direct photoreduction and the reduction unrestrained with nitrous oxide were examined by effects of oxygen, nitrous oxide, hydrogen peroxide and optical filter. The results suggested that ferricytochrome c could be reduced by UV light through excitation of certain aromatic amino acid residues in the molecule and by hydroxyl radicals converted from hydrated electrons via reaction with nitrous oxide.View full abstractDownload PDF (389K) -
K. KAWAI, H. MAKI, M. AKABOSHI1977 Volume 18 Issue 4 Pages 268-274
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSAn absorbed dose in amoeba irradiated by thermal neutrons was estimated. Nuclear events following to thermal neutron capture were divided into 6 parts. More than 99% of absorbed dose was estimated to be due to capture γ-rays. Absorbed dose due to recoil nucleus following to the emission of capture γ-rays and that due to β- or γ-rays emitted at the nuclear disintegration of newly formed radioactive nuclides were about 1/1000 of that of capture γ-rays. Anyhow, the absorbed dose obtained by these calculation is too small to explain the lethal effects of thermal neutrons on amoeba. Therefore another processes than energy absorption, namely, transmutation effects due to thermal neutron capture and nuclear disintegration must be taken into account. Especially, the bond rupture on thermal neutron-irradiated DNA, caused by the nuclear reaction 31P(n, γ)32P, would play a very important role in cell killing of amoebae.View full abstractDownload PDF (314K) -
T. OHNO, T. SAEKI, M. URANO, I. WATANABE, M. SHIKITA1977 Volume 18 Issue 4 Pages 275-279
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSDuring the course of surveying electron affinic sensitizers, we found that furylfuramide (AF-2) showed an apparent sensitizing effect in vitro on hypoxic mouse L5178Y cells irradiated with 900 rads of X-rays but it did not sensitize the cells at less than 600 rads. Sensitizing activity of AF-2 was confirmed in vivo by a single dose (3500 rads) of X-rays on mouse mammary carcinoma, though it failed to sensitize the tumor cells when the radiation was given as multiple fractions. These results present an extreme case for hypoxic sensitizers which had no or decreased potency of sensitization in the low dose range around the shoulder region of survival curves for the irradiated cells.View full abstractDownload PDF (197K) -
ASHOK KUMAR, P. N. SRIVASTAVA1977 Volume 18 Issue 4 Pages 280-292
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSRadiophosphorus was injected to mice at various stages of development (1 day, 1, 2, 3 and 4 weeks) at the dose-rate of 1.0μCi/g body weight. Animals were autopsied at weekly intervals upto six weeks and quantitative study of pronormoblast, normoblast, granulocyte and lymphocyte counts have been made.
The erythroid cells show rapid decrease in their percentage due to irradiation. The myeloid cells undergo accelerated maturation resulting in increased percentage of segmented forms in bone marrow. The percentage of lymphocytes is also decreased. The regeneration sets in and a normal picture is seen by the time the animals become adult.View full abstractDownload PDF (476K) -
KEN-ICHI IJIRI1977 Volume 18 Issue 4 Pages 293-301
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSEmbryos of the fish Oryzias latipes at stage 28 were irradiated with 2000 rad γ-rays, and the time-course changes in germ-cell numbers and their nuclear diameters were studied. The germ-cell numbers remained essentially unchanged throughout the subsequent developmental stages examined up to 2 days after hatching. During such stages, germ cells with an enlarged nucleus were observed in irradiated germ-cell population. Quantitative studies on the changes in their nuclear diameters revealed that the appearance of enlarged nuclei reached its maximum percentage at the hatching time (112 hr after irradiation), and such swelling of nuclei had already started in the primordial germ cells at 48 hr after irradiation.View full abstractDownload PDF (347K) -
B. R. SAHARAN, R. P. SINGH, A. VERMA1977 Volume 18 Issue 4 Pages 302-307
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSUndertaken study deals with any vulnerable changes by the radioprotective drug 2-mercaptopropionylglycine, after administering in variable concentration (20, 50, 100, 200 and 500 mg/kg body weight) of the liver of adult mice at 1, 3, 7 and 14 days interval. The lower doses, 20 and 50 mg/kg body-weight of MPG did not affect the liver at all while at higher doses of 100, 200 and 500 mg/kg body-weight of MPG, liver showed many histopathological changes in the form of cytoplasmic degranulation and vacuolation, pyknotic, necrotic, crenated and hypertypic nuclei, hyperaemia, and lymphocytic infiltration etc. These damages were found to be irreversible at the dose level of 500 mg/kg body-weight at the last interval studied.View full abstractDownload PDF (419K) -
B. R. SAHARAN, P. UMA DEVI1977 Volume 18 Issue 4 Pages 308-316
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe histopathological changes in the testes of adult Swiss albino mice exposed to a sublethal dose (500 R) of gamma rays after an intraperitoneal injection of 20 mg/kg body-weight of 2-mercaptopropionylgycine (MPG) were studied. The results have been compared with those obtained from animals irradiated with the same dose of gamma rays in the absence of drug. It was found that the drug delayed the disappearance of male germ cells and accelerated the regeneration of seminiferous epithelium when administered 15-30 minutes before irradiation. Histopathological changes were of much lesser degree in comparision to control. These results are discussed in the light of relevant literature.View full abstractDownload PDF (592K) -
M. KOMURO1977 Volume 18 Issue 4 Pages 317-321
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe ovarian tumors induced by X-ray irradiation were histologically examined in ddY/F and C3H/Tw strains of mice 15 months after irradiation. Luteomas were developed predominantly in ddY/F mice after whole-body irradiation and tubular adenomas in C3H/Tw mice. However, when one ovary was shielded from irradiation in ddY/F mice, no ovarian tumors were found in any of the irradiated contralateral ovaries. After the removal of the normal ovary at 1 or 6 months after irradiation, the increase in the incidence of tubular adenomas and the decrease of the luteomas were resulted in ddY/F mice when examined at 15 months after irradiation. No tumors were induced in the ovaries which were grafted subcutaneously after the X-ray irradiation of the recipient. These results suggested that hormonal conditions especially during early stages of tumorigenesis may determine the type of ovarian tumors.View full abstractDownload PDF (358K) -
R. NAKAMURA, Y. SUZUKI, T. UEDA1977 Volume 18 Issue 4 Pages 322-330
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSDistributions of radionuclides among green alga (Ulva pertusa), marine sediment and sea water were examined in laboratory experiments with radioisotope tracers to look into the behavior of the radionuclides released into the coastal sea. Marine sands from the five different seashores along the coast of Japan were used. Distributions of 60Co, 95Zr 95Nb and 106Ru- 106Rh in these sands were by far the highest of the three components (marine sand, sea water and marine alga). The distributions of the three radionuclides had not so large fluctuations among the five marine sands and were considered to be rather constant. The total amount found in marine sand and green alga was about 90% for the three radionuclides but about 20% for 137Cs on the average in two weeks after the start of the experiments. The activity ratio of marine sediment (radioactivity in 1 g of sediment/radioactivity in 1 ml of sea water) was 4000 for 60Co, 30 for 137Cs, 1800 for 95Zr- 95Nb and 900 for 106Ru- 106Rh.View full abstractDownload PDF (336K) -
I. AOYAMA, Y. INOUE1977 Volume 18 Issue 4 Pages 331-341
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSConcentration of radionuclides in aquatic organisms is affected by various environmental and phisiological factors. The concentration factor is, cosequently, widely ranged.
In this paper, uncertainty on the concentration process of radionuclides by organisms was evaluated from the viewpoint of the statistic and the information theory. The concept of entropy was introduced as a measure of uncertainty of information and an information source of the stochastic process on the basis that the distribution of the concentration in organisms obeyed the Poisson distribution and that its change with time could be expressed by the stochastic process. Entropy was calculated by a following equation as a measure of the uncertainty in predicting the most reliable state of con -entration step in aquatic organisms out of n states when the frequency distribution of the concentration Q(q1, q2……qn)was obtained,
H(qi)=-∑ni=1qilog2qi,
where qi is the probability of the state i.
It was found that the entropy of the state vector which expresses the concentration step increases with time and that the entropy of the state i and the information source of the Markov Chain decreases inversely.
This paper also presents the sample size necessary for obtaining the statistically significant result when aquatic organisms are taken as an indicator of radioactive contamination in environment.View full abstractDownload PDF (365K) -
M. KUWABARA, M. HAYASHI, G. YOSHII1977 Volume 18 Issue 4 Pages 342-347
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSWhen the solid-state deoxyribonucleoprotein (DNP) was irradiated by gamma rays, Lücke-Huhle et al.1) found that single strand breaks of DNA were produced more frequently in the DNP than in pure DNA. Ormerod2) and Kuwabara and Yoshii3) reported that the ESR spectra of DNP after irradiation showed radicals to be located preferentially on the DNA moiety, and the results were explained by the electron transfer from the protein moiety to the DNA moiety. From studies on the luminescence decay curve of DNP when irradiated with electron pulses, Lillicrap and Fielden4) also found that the excitation energy formed in the protein moiety was transferred to the DNA moiety.
When the DNP solution was irradiated by gamma rays, Weiss and Wheelers5) and Hayashi et al.6) found that the template activity of DNP for RNA synthesis was considerably enhanced by irradiation (10-20 krad), whereas Hagen et al.7) found that the template activity of purified DNA was markedly reduced. Using an irradiated DNP template, Mee et al.8) also reported that changes in the base composition of the synthesized RNA were found at doses of 10-20 krad.View full abstractDownload PDF (233K) -
S. YAMAGUCHI1977 Volume 18 Issue 4 Pages 348-352
Published: November 30, 1977
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSA rapid and sensitive method of the neutron activation analysis in pineapples is described. Younger stems contained the most Cl and Br than the other older stems. Analysis indicates that senescence is correlated with an increase in content of Br and Cl.View full abstractDownload PDF (159K)
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