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Volume 35 (1994)
- Issue 4 Pages 205-
- Issue 3 Pages 139-
- Issue 2 Pages 65-
- Issue 1 Pages 1-
Volume 35, Issue 2
Displaying 1-7 of 7 articles from this issue
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NORIHIKO KITADA, KIYOSHI AKAGI, YOSHIMASA TANAKA, BERNHARD FRITZ-ZIERO ...1994 Volume 35 Issue 2 Pages 65-73
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSThe usefulness of 31P-MRS (phosphate magnetic resonance spectroscopy) for evaluation of the anti tumor effect of hyperthermic treatment was examined. FM3A, an experimental tumor transplantable to C3H mice, was used. FM3A, transplanted subcutaneously to the femoral region, was subjected to hyperthermic treatment and 31P-MRS were measured at various times. Because the ATP/Pi ratio indicates the energy status of tumor cells, we conducted measurement of its sequential changes after hyperthermic treatment. With a water bath, hyperthermic treatment was performed at 44°C.
Twenty four hours after treatment, the ATP/Pi ratio dropped as the heating time was prolonged, showing an obvious converse correlation to the tumor growth curve on heating. Immediately after hyperthermic treatment, the ATP/Pi ratio fell drastically, began to recover after 18 hrs and remained unchanged up to the 24 hrs. The finding that the ATP/Pi ratio obtained in tumor tissue 24 hrs after hyperthermic treatment was correlated with tumor inhibition suggested that the ratio can be a possible parameter for evaluation of the anti tumor effect by heating. The ATP/Pi ratio obtained by 31P-MRS could be used for non-invasive prediction of tumor tissue damage by heating.View full abstractDownload PDF (321K) -
CHIHIRO KOSHIMOTO, SENTARO TAKAHASHI, YOSHIHISA KUBOTA, HIROSHI SATO1994 Volume 35 Issue 2 Pages 74-82
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSRat fetuses at day 14 of gestation were irradiated externally with gamma rays at doses of 0.5-8 Gy, and the effect of radiation on the transfer of the erythropoietic site with migration of stem cells from the blood islands of the yolk sac into the liver was investigated. The LD50 was about 5 Gy for 16-day-old fetuses, 2 days after irradiation. Such fetal hematological parameters as the number of blood cells in the liver and the formation rate of micronuclei in erythrocytes, also were affected by irradiation. Two types of blood cells were present in the fetal circulating blood; small blood cells originating in the fetal liver and large blood cells originating in the blood islands of the yolk sac. The number of small blood cells in the circulating blood decreased with the increase in the radiation dose; but, the number of large blood cells remained relatively constant. This suggests that external doses of irradiation of more than 1 Gy impaired the normal transfer of the hematopoietic site (stem cell migration from the blood islands of the yolk sac into the liver).View full abstractDownload PDF (415K) -
YUKO IBUKI, RENSUKE GOTO1994 Volume 35 Issue 2 Pages 83-91
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSThe effect of whole-body irradiation with low doses of γ-rays was investigated for the Con A-induced proliferation of splenocytes. Proliferation was enhanced by 0.02Gy irradiation, but was inhibited by 0.2Gy. The enhanced proliferation produced by low-dose irradiation also was studied using co-cultures of splenolymphocytes and peritoneal macrophages (Mφs) instead of spleno-Mφs. The proliferative response of spleno-lymphocytes was not affected by low doses of γ-ray irradiation; whereas, the responses of unirradiated spleno-lymphocytes cultured with the peritoneal Mφs that had been irradiated at 0.02 and 0.04Gy respectively were about 120 and 145% of the control. Proliferative enhancement was found when peritoneal Mφs collected 4h after whole-body irradiation were used, but not with those collected at 1 and 12h. No enhancement took place when in vitro irradiation was used. These results suggest that the enhancement in Con A-induced proliferation of splenocytes by low-dose irradiation was caused not by the activation of spleno-lymphocytes, but by activation of spleno-Mφs, and that the Mφs were activated indirectly.View full abstractDownload PDF (417K) -
KEISUKE S. IWAMOTO, YUKO HIRAI, SHIGEKO UMEKI, YOICHIRO KUSUNOKI, SEIS ...1994 Volume 35 Issue 2 Pages 92-103
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSDose estimates for the assessment of future risks, following accidental exposure to radiation, for certain diseases such as cancer usually rely on both physical and biological quantitative analyses. A traditional biological method of choice is the measurement of chromosome aberration frequencies in peripheral-blood lymphocytes. However, thorough examination of large sample populations is time and labor intensive. Recently, it became possible to measure mutant frequencies in T lymphocytes; one method is a colony assay at the HPRT gene, and the other is a flow-cytometric assay at the T-cell-receptor (TCR) gene. To test for the possible use of these mutation assays, concurrent measurements were taken on blood samples from women who previously received a full course of radiation therapy for gynecological cancer. The results showed that the frequency of TCR mutants correlated reasonably well with that of dicentric chromosomes, whereas the frequency of HPRT mutants did not. Possible uses of the TCR mutation assay in combination with the conventional chromosome analysis or micronucleus assay after exposure of a relatively large population are discussed.View full abstractDownload PDF (523K) -
KOTARO HIEDA, KEIJI SUZUKI, TAISUKE HIRONO, MASAO SUZUKI, YOSHIYA FURU ...1994 Volume 35 Issue 2 Pages 104-111
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSSolid pBR322 DNA was irradiated in a vacuum by monochromatic photons from 8.3 eV (150 nm) to 20.7 eV (60 nm), and the formation of single and double-strand breaks (ssb and dsb) was determined using agarose gel electrophoresis. The action cross sections increased 20 times (ssb) and 43 times (dsb) from 8.3 eV to 20.7 eV; the quantum yields increased 5.4 times (ssb) and 12 times (dsb). The cross sections for dsb were 0.0059 at 8.3 eV and 0.013 at 20.7 eV of those of ssb; these values were smaller than about 0.04 for 2.1 keV photons, or about 0.18 for 60Co γ-rays. Although vacuum UV photons were proved to induce dsb, they had a lower efficiency than when using soft X-rays or γ-rays.View full abstractDownload PDF (319K) -
SHUN''ICHI HISAMATSU, YOSHIKAZU INOUE, YUKIO TAKIZAWA1994 Volume 35 Issue 2 Pages 112-115
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSOrganically-bound 3H (OBT) concentrations in unhulled rice samples harvested between 1979 to 1991 are reported. The sample reaped in 1979 had the highest OBT concentration. OBT concentrations in the samples yielded recently have been at approximately 1 Bq (L-combustion water)-1 or less.View full abstractDownload PDF (150K) -
H. WATANABE, J. H. HENDRY1994 Volume 35 Issue 2 Pages 116-122
Published: June 15, 1994
Released on J-STAGE: May 19, 2006
JOURNAL FREE ACCESSThyroid cells were given 5.5 Gy X-rays in situ and transplanted after 1 day or after 6 weeks to form colonies in fat pads. The colony-forming efficiency unexpectedly decreased by a factor of about 2 with this increase in delay time before transplantation. In addition, there was a concomitant marked increase above the control levels in the proportion of new structures of thyroid origin containing abnormal follicles. These quantitative and qualitative increases in injury may be related to the gradual expression of thyroid abnormalities following irradiation in situ, and they may have implications for the recovery of functional tissue subunits in other organs.View full abstractDownload PDF (397K)
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