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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 4
Displaying 1-12 of 12 articles from this issue
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KIHEI KUBO, SOICHIRO KOIWAI, KAZUO MORITA1985 Volume 26 Issue 4 Pages 361-371
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe contribution of caffeine-modifiable repair process to the radio sensitivity of a radioresistant HeLa strain (RC-355) has been investigated in comparison with control HeLa strain (CC-24). Both the final slope and the shoulder of X-ray survival curve for log-phase cells were affected by caffeine posttreatment. When the treatment with 10 mM caffeine delayed, an increase in survival was observed with increasing interval between irradiation and the treatment. During first several hours of the repair interval, the steepness of the final slope of survival curve decreased rapidly, and rate of the decrease was found to be higher in RC-355 than in CC-24 cells. Longer time (24 hours or more) before the initiation of caffeine treatment was required for the complete recovery of the shoulder. When the cells were incubated in plateau-phase after irradiation, an appreciable increase in survival was observed in comparison with when plated immediately following X-ray. The increase was found to be greater for RC-355 than for CC-24. The results suggest that the radioresistant RC-355 cells repaired more X-ray-induced PLD than CC-24 cells did.View full abstractDownload PDF (481K) -
NOBUO ODA, SHIGERU IWANAMI1985 Volume 26 Issue 4 Pages 372-384
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSA calculation method of frequency distributions for the microdosimetric quantity J (number of effective primary events produced in a target), hJ, is presented. This method is briefly compared with other approaches developed by Kellerer and Chmelevsky, and Wilson and Paretzke for numerical calculations of microdosimetric quantities. The hj distributions are calculated for nanometer-size targets in water irradiated with 60Co γ rays as a practical application. It was found that the hJ distribution remarkably depends on two parameters, Dσ0 and 1/W'', where D is the absorbed dose, σ0 is the mean geometrical cross section of the target, 1 is the mean target thickness, and W'' is the mean energy to produce an effective primary event in the target. Our hJ distributions are compared with those in the conventional target theory. Finally, the quantity z'' and the frequency distribution for z'', hz'', which correspond to the specific energy z and the probability density f(z) defined in ICRU Report 36, are derived from J and the hJ distribution, respectively. The hz'' distribution depends on the values of Dσ0 and 1/W'' and the frequency mean of z'', z'', is equal to the absorbed dose D.View full abstractDownload PDF (539K) -
MARIA KOWALSKA1985 Volume 26 Issue 4 Pages 385-394
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThree generations of rats were long-term exposed to HTO in drinking water at activity of 37.0 kBq/ml or to food containing OBT at activity of 48.1 kBq/g. The rats consumed tritiated water and tritiated food ad libitum. In the experiment the F1 and F2 generation of rats were exposed continuously from conception to the 21-st or 120-th day of age and rats of F3 generation during 22 days of their intrauterine life. It was found that the amount of tritium incorporated into the major rat brain phospholipids and gangliosides after administration of tritiated food was higher than after administration of tritiated water. Tritium activity in all studied phospholipids and gangliosides was the highest in 21-day-old rats exposed during both-pregnancy and lactation.View full abstractDownload PDF (429K) -
S. K. BASU, M. N. SRINIVASAN, K. CHUTTANI, A. GHOSE1985 Volume 26 Issue 4 Pages 395-403
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSSurvival studies were carried out after 8 Gy whole body gamma radiation (WBGR) in rats treated either with Solcoseryl, β-mercaptopropionyl glycine (MPG), 2-aminoethylisothiuronium bromide hydrobromide (AET), 5-hydroxy L-tryptophan (5-HTP), MPG+5-HTP or AET+5-HTP. The drugs were tested after either oral or i.p. administration in fasted rats. Solcoseryl and the combinations of 5-HTP with AET or MPG rendered excellent protection against 8 Gy but lower survival against 10 Gy WBGR. Oral ingestion of these combinations also gave effective protection against 8 Gy whole body gamma radiation.View full abstractDownload PDF (320K) -
YUTA SHIBAMOTO, CHIKARA KOMURO, MASAJI TAKAHASHI, KOJI ONO, MITSUYUKI ...1985 Volume 26 Issue 4 Pages 404-410
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe inhibitory effect of N6-butyrylcordycepin (7904), one of purine nucleoside analogues, on potentially lethal damage repair (PLDR) in vivo was tested using two experimental tumors, EMT6 sarcoma and SCCVII carcinoma, by an in vivo-in vitro assay. The drug had been reported to be the most potent PLDR inhibitor in vivo. In both tumors, PLDR was apparent in the experimental dose range of 15-35 Gy. However, 100 mg/kg and 200 mg/kg of the 7904 had no inhibitory effect on PLDR in EMT6 tumors, and 200 mg/kg had little effect in SCCVII tumors. Measurement of drug concentrations in the blood by high-performance liquid chromatography showed a low peak level and a relatively short half-life. This was considered to be a cause of the ineffectiveness in vivo.View full abstractDownload PDF (278K) -
YOSHIYA SHIMADA, AKIHIRO SHIMA, NOBUO EGAMI1985 Volume 26 Issue 4 Pages 411-417
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe embryos of the fish Oryzias latipes at 3 days after fertilization were irradiated with 10 Gy gammarays after the environmental stresses such as heat-shock, the release from hypoxia, cadmium or arsenite treatment, and change in germ cell number at hatching was determined. Heat-shock (37-42°C, 30 min) could develop radiation resistance increasingly with an increase in the temperature of the heat-shock. However, the release from hypoxia and cadmium or arsenite treatment, which are known to induce heat-shock proteins as well as thermotolerance did not affect the radio sensitivity at all.View full abstractDownload PDF (264K) -
TOHRU NAKAZAWA, SHINICHIRO NAGATSUKA, OSAMI YUKAWA1985 Volume 26 Issue 4 Pages 418-425
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSEffects of γ-radiation on the physical state of membranes were examined with liposomes of lecithin (phosphatidylcholine) from soybean and rat liver microsomes using spin labeling method. There was a slight increase in the membrane fluidity after irradiation. However, a marked decrease in the membrane hydrophobicity by irradiation was observed in the peripheral region in both types of membranes, in parallel with an increase in the lipid peroxidation. These results suggest that irradiation mainly causes a decrease in the membrane hydrophobicity through lipid peroxidation.View full abstractDownload PDF (352K) -
KENSHI KOMATSU, KIYOHIKO SAKAMOTO1985 Volume 26 Issue 4 Pages 426-435
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe ability of dibucain, a local anesthetic, to enhance the cytotoxicity of and the repair of potentially lethal damage induced by pepleomycin or X-rays has been studied in exponential and plateau phase cultures of Chinese hamster cells. No enhancement of X-ray cytotoxicity or inhibition of repair from X-ray injury was observed, but dibucain produced very significant enhancement of pepleomycin effectiveness. In both cases the effects induced were larger in the exponentially growing cells than in the plateau phase cells. Greater than 20-fold increases in the cytotoxic effectiveness of pepleomycin, and greater than 10-fold differences in survival after the cells had been allowed to repair the potentially lethal damage induced by pepleomycin were observed when the cells were treated with dibucain. The possible mechanisms underlying this enhancement are discussed.View full abstractDownload PDF (342K) -
MORIO YONEZAWA, NORIO KATOH, ATSUHIKO TAKEDA1985 Volume 26 Issue 4 Pages 436-442
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSA single post-irradiation injection of the thermostable fraction of a ginseng extract enhanced the recoveries of the numbers of both blood-forming stem cells (10 days CFUs) and megakaryocytes in bone marrow of irradiated mice. It also protected hemorrhaging tendency of X-irradiated mice determined by a quantitative measurement of occult blood appearance in daily feces.
The present study and our previous findings suggest that ginseng protected the irradiated animals from bone marrow death by stimulating thrombopoietic hematogenesis (CFUs, megakaryocytes and thrombocytes) and finally preventing hemorrhage.View full abstractDownload PDF (228K) -
YOSHISADA FUJIWARA, MASAMITSU ICHIHASHI, YOSHIHIKO UEHARA, AKIRA MATSU ...1985 Volume 26 Issue 4 Pages 443-449
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe differential bead-labelling method for heterodikaryon complementation enabled us to allocate xeroderma pigmentosum patients XP40KO and XP38KO to complementation groups C and F, respectively. Group C XP40KO cells exhibited 15% UDS and the 5 and 1.5-fold hypersenstivities to UV and 4-nitroquinoline-1-oxide (4NQO) killings, respectively, while group F XP38KO cells showed a higher residual level of 20-25% UDS and a less UV/4NQO hypersensitivity than did the previously assigned group F strains. We reviewed the thus far assigned Japanese groups C and F subjects for the repair and clinical characteristics. The present group C XP40KO was typical, while XP38KO was heterogrnous within group F with respect to repair.View full abstractDownload PDF (297K) -
MITSUHIKO AKABOSHI, KENICHI KAWAI, HIROTOSHI MAKI1985 Volume 26 Issue 4 Pages 450-458
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSEhrlich ascites tumour cells were irradiated in vitro with thermal neutrons under aerobic and hypoxic conditions, and the survival of their reproductive capacity was assayed in vivo. Only a slight hypoxic protection was observed for thermal neutron irradiation with an oxygen enhancement ratio (OER) of 1.2, as compared with OER of 3.3 for 60Co-γ-rays. Absorbed dose of thermal neutrons was calculated by assuming that the energies of recoiled nuclei were completely absorbed within a cell nucleus. This led to a conclusion that the RBE of thermal neutrons were 1.3 and 3.6 for the oxygenated and the hypoxic cell fractions, respectively.View full abstractDownload PDF (375K) -
HIROSHI MITANI1985 Volume 26 Issue 4 Pages 459-463
Published: December 15, 1985
Released on J-STAGE: June 16, 2006
JOURNAL FREE ACCESSThe sensitivities of three goldfish-cell lines to the lethal effects of four carcinogens/mutagens; 4-nitroquinoline-1-oxide (4NQO), 1-methyl-3-nitro-l-nitrosoguanidine (MNNG), mitomycin C (MMC) and bleomycin (BLM), were compared using colony-formation assay. RBCF-1 and CAF-MM1 cells were more sensitive to 4NQO, BLM and UV than were GEM 199 cells. CAF-MM1 and GEM 199 cells showed almost the same sensitivity to MNNG, while the RBCF-1 cells were more sensitive. RBCF-1 cells were also the most sensitive to MMC and BLM among the three. This suggests that there may be some defect in DNA repair system in RBCF-1 cell line.View full abstractDownload PDF (202K)
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