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Volume 26 (1985)
- Issue 4 Pages 361-
- Issue 3 Pages 257-
- Issue 2 Pages 151-
- Issue 1 Pages 99-
Volume 26, Issue 2
Displaying 1-10 of 10 articles from this issue
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LI DEPING1985 Volume 26 Issue 2 Pages 151-168
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSAfter an outline of activities, publications and contributing organizations in the field of research in biological effects of radiations, a brief description to the Institute of Radiation Protection, MNI, -one with 8 research divisions and 1 affiliated hospital is given. Then topics more closely connected with radiation protection are reviewed. Animal experiments with various biological end points are performed to determine the n to gamma RBE''s, and their additivities are examined. In chromosome aberration studies, groups with significantly lower natural aberration rates are reported. Radon daughters deposited in the lung are ineffective in inducing chromosome aberration in circulating blood cells. Through determination of break repairing time, doserate effect can be corrected for exposure time up to several hours, this is of value to accident dose estimation. Experiences with biological dosimetry are discussed. Some results of the high background area survey and the preliminary survey in high cosmic ray area are presented. The stem cell survival rate weighted doses correlate close to the clinic findings in some published cases of accident overexposures, and they are insensitive to bone marrow distribution and survival curve parameters. Experiments with partially shielded dogs support this concept. Works on effective dose equivalent are briefly described. Doses, or dose distributions, to specified cells at risk in organs such as thyroid or lung, have been calculated with necessary parameters determined experimentally. Other topics such as some works on radiation ecology and effects of microwave to animals are included.View full abstractDownload PDF (530K) -
A. F. G. STEVENSON1985 Volume 26 Issue 2 Pages 169-176
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe influence of dose-rate (DR) (either 5.2 or 52 cGy/min.) on the regeneration of bone marrow (BM) myelopoietic progenitor cells was studied in beagles after exposure to whole-body-irradiation (235, 375 and 1500 cGy + autologous BM-transplantation). Myelopoietic progenitor cells were assayed as colonyforming units in agar cultures (GM-CFU), in correlation with the colony-stimulation activity (CSA) in serum. At 235 cGy, the influence of DR on the recovery of GM-CFU was insignificant. However, at 375 cGy, the recovery was critically dependent on the DR. Depletion of GM-CFU numbers elevated CSA levels above preirradiation values. The DR determines the regenerative ability when the dose itself is critical to survival of the least number of hematopoietic stem cells (HSC) necessary for restitution.View full abstractDownload PDF (398K) -
A. F. G. STEVENSON, K. WERDAN, T. CREMER, K. LEHNER, O. MESSERSCHMIDT1985 Volume 26 Issue 2 Pages 177-188
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSAs protein molecules constitute 60% by mass of all membranes, one might expect to detect radiationinduced lesions in this compartment. The efficiency of the two carrier-proteins for D-glucose and glycine were determined post-irradiation (p.r.). A finite line of human diploid fibroblasts was used for this purpose. Quiescent Phase II cultures were exposed to 1, 5, 10, 30, 50 and 100 Gy X-rays and to 2.103 and 5.103 Gy 60Co-γ-rays. For each given dose, cells were detached enzymatically for measurements of their transport capabilities at time-intervals ranging from 30 mins. to 21 days p.r. The affinity to substrate (KM), maximal transport rate (Vmax) and the rate constant of the non-saturable component (KNS) were measured. Vmax varied depending on the criterium considered i.e. maximal transport rate per cell number, per unit volume cell space and per unit area cell surface. This incongruity was due to the concomitant increase in cell volume with time p.r. Soon after irradiation and even days later, no impairment in either Vmax or KM was detectable for either D-glucose or glycine for doses up to 100 Gy. At doses of 2.103 and 5.103 Gy, a 50% decrease in Vmax was observed. KM remained constant throughout.View full abstractDownload PDF (573K) -
S. K. BASU, M. N. SRINIVASAN, K. CHUTTANI, A. BHATNAGAR, A. GHOSE1985 Volume 26 Issue 2 Pages 189-195
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSDose response relationships of creatine, creatinie excretions and their ratio in 24 hr urine samples have been studied on each individual day upto 4 days after 1-7 Gy whole body gamma irradiation to rats. Creatine excretion reaches the peak on the 2nd day while creatinine excretion reaches the peak on the first day and a plateau is maintained upto the 4th day in each case. Good dose response correlationship is maintained for creatine or creatinine levels upto the 4th day and for creatine creatinine ratio upto the 3rd day. Seperate dose response curves are needed on each individual day for using these parameters for biological dosimetry purpose.
Administration of the radioprotectors viz., combination of 5-hydroxytryptophan (HT) and 2-amino-ethylisothiuronium bromide hydrobromide (AET), HT alone and optimum radioprotecting dose of AET before 5 Gy whole body γ-irradiation have not been of help for reducing creatinineurea.View full abstractDownload PDF (266K) -
JUNKO MIYAJIMA, SHUNZO OKAJIMA, HIDEAKI TAKAO, AKIHISA NAKASHIMA, ZENI ...1985 Volume 26 Issue 2 Pages 196-210
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe deposits of thorium dioxide in Thorotrast patients are observed in the reticulo-endotherial system, such as liver and spleen. The amounts of deposits in patients can be estimated by a whole body counter, but hospitals which have the apparatus are few. In this study the method for the estimation of thorium dioxide deposited in Thorotrast patients by a computed tomography (CT) scanner was examined and established. A relationship between the activity of Th-232 per volume and the CT number was determined with CT phantom experiments. The activity of Th-232 per volume of the spleen and the liver of Thorotrast patients were estimated by the relationship and their absorbed dose rates were evaluated. The estimates by the CT scanner were compared with those by the whole body counter. The estimates by the CT scanner of the activity per volume which is related to the absorbed dose rate was more accurate than that by the whole body counter. In the case of CT scanner, the distribution of thorium deposited in the body was obtained.View full abstractDownload PDF (526K) -
MASAYOSHI YAMAMOTO, KAZUHISA KOMURA, MASANOBU SAKANOUE, MASAHARU HOSHI ...1985 Volume 26 Issue 2 Pages 211-223
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSPlutonium Isotopes, 241Am and 137Cs in soil samples collected from Nagasaki and Hiroshima were measured to evaluate the contribution of residual radioactivity derived from the atomic bombs dropped in 1945.
In the soils from Nishiyama area of Nagasaki City, activity ratios different from those of global fallout were found for the 238Pu/239, 240Pu (0.05-0.06), 239, 240Pu/137Cs (0.2-0.3), 241Am/239, 240Pu (0.04-0.05) and 240Pu/239Pu (0.08-0.13), activity ratios indicating that a fair amount of plutonium derived from the atomic bomb had accumulated in this area. On the other hand, in the soils from the “Black-rain” area of Hiroshima, no significant difference from the global fallout was found for the activity ratios among the Pu isotopes, 241Am and 137Cs except for the soils collected at 10 km and 12 km in the NNW direction from the epicenter, where a factor 2 to 3 lower 241Am/239, 240Pu activity ratio was observed. However, no evidence of the contribution of the atomic bomb was found by the measurement of 240Pu/239Pu isotopic ratio.View full abstractDownload PDF (453K) -
D. ENDOH, M. KUWABARA, F. SATO, G. YOSHII1985 Volume 26 Issue 2 Pages 224-232
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSAfter calf thymus DNA was gamma-irradiated in the solid state in vacuo and subsequently dissolved in aqueous solution containing misonidazole (3 mM) under hypoxic condition, the frequency of single-strand breaks and alkali-labile sites in DNA and the amount of misonidazole bound to DNA were measured. The presence of misonidazole converted the precursor radicals, which otherwise results in single-strand breaks, to alkali-labile sites, and the amount of alkali-labile sites increased linearly with increasing radiation dose. The amount of misonidazole bound to DNA also increased linearly with increasing radiation dose. The biological meaning of the changes in the frequency of single-strand breaks and alkali-labile sites by the reaction of misonidazole with DNA radicals and of binding misonidazole with DNA was examined using a model system to measure the template activity of DNA for RNA synthesis in vitro. The conversion of DNA radicals to alkali-labile sites protected the radiation-induced decrease in the template activity of DNA, while the adduct formation of misonidazole had no effect on it.View full abstractDownload PDF (337K) -
Effects of 2''-Chlorothymidine on Chinese Hamster Cells Irradiated with X-Rays and Ultraviolet LightT. MURAI, K. KUBO, M. KUWABARA, T. ITOH, G. YOSHII, F. SATO1985 Volume 26 Issue 2 Pages 233-237
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSEffects of 2''-chlorothymidine (2''-Cl-TdR) and its mother compound, thymidine (TdR), on cell killing induced by X and UV-irradiation have been investigated. Chinse hamster V-79 (TK+) cells as well as thymidine kinase deficient (TK-) variant cells, which were isolated from parental V-79 cells following stepwise treatment with BUdR, were incubated in a medium containing 2''-Cl-TdR and TdR after X and UV-irradiation. In the TK+ cells, both 2''-Cl-TdR and TdR enhanced the killing efficiency of X-rays and ultraviolet light. On the other hand, in the TK- cells, only 2''-Cl-TdR enhanced the killing efficiency of X and UV-irradiation, and no effect of TdR was observed. These results suggest that phosphorylation of TdR by the enzyme is essential for its ability to modify radiation response, while the enhancement of cell killing by 2''-Cl-TdR must be explained by a mechanism at least partly independent of phosphorylation.View full abstractDownload PDF (249K) -
JUNJI MIYAKOSHI, WASAKO ODA, YOWRI UJENO, CHIYOKO INAGAKI1985 Volume 26 Issue 2 Pages 238-247
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSModification of thermal sensitivity by deuterated water (D2O) was examined in Chinese hamster V-79 cells. When cells were exposed to hyperthermia at 44°C in a medium containing 20 to 85% D2O, cell survival was remarkably increased. Thus, D2O applied during hyperthermia resulted in thermal protection. However, when cells were treated with D2O (50%) medium for 4 to 24 hours and then exposed to hyperthermia in normal medium, thermal sensitization was observed. Increasing interval time at 37°C between D2O and hyperthermic treatments, the thermal sensitization was rapidly reduced and reached to the normal level in about 4 hours of the interval. On the other hand, thermotolerance induced during step-up heating (42 → 44°C sequence) was reduced by pretreatment of cells with 50% D2O medium for 4 or 24 hours. In split hyperthermia (44 → 44°C sequence) experiments, when cells were incubated at 37°C for 24 hour-interval in 50% D2O medium, survival of cells was markedly reduced, and the shoulder of the survival curve almost disappeared. Thus, thermal sensitization also was observed with pretreatment of the cells with D2O.View full abstractDownload PDF (391K) -
G. C. POGANY, K. C. LEWIS1985 Volume 26 Issue 2 Pages 248-256
Published: June 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe irradiation of mouse testes at 600 rads is accompanied by extensive tissue destruction which ultimately results in a 70% loss of organ weight but displays appreciable recovery which is usually complete by week 18. The attrition phase of testicular weight is concurrent with a conspicuous elevation in cathepsin B activity. This is interpreted to reflect the extensive proteolysis that must form the basis for such tissue weight loss. The recovery period, in contrast, is characterized by an attenuation in the activity of the enzyme. Further analyses reveal that the rise in hydrolytic activity is not due to lysosomal membrane breakage. Nor does it seem to be related to an increase in the number of lysosomes. Instead, our data are more consistent with the contention that the rise in cathepsin B activity may be associated with an increase in protein synthesis. As a result, some lysosomes may contain a larger number of enzyme molecules. This hypothesis is supported by our demonstration that radiation induces a distinct shift in the density of lysosomes toward the heavier components. The significance of such radiation-induced enhancement of protein synthesis in terms of a general response of tissues to radiation damage is discussed.View full abstractDownload PDF (443K)
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